1 设计简介

SPI（Serial Peripheral Interface）串行外围设备接口总线系统，是一种高速的，全双工，同步的通信总线，它可以使MCU与各种外围设备以串行方式进行通信以交换信息。SPI总线系统可直接与各个厂家生产的多种标准外围器件直接接口，主要应用在 EEPROM，FLASH，实时时钟，AD转换器，还有数字信号处理器和数字信号解码器之间。

SPI总线系统接口信号如下：

（1）SDO –主设备数据输出，从设备数据输入

（2）SDI –主设备数据输入，从设备数据输出

（3）SCLK –时钟信号，由主设备产生

（4）CS –从设备使能信号，由主设备控制

SPI的通信原理简单，以主从方式工作，这种模式通常有一个主设备和一个或多个从设备，需要4根线，并且在芯片的管脚上只占用四根线，节约了芯片的管脚，同时为PCB的布局上节省空间，提供方便，正是出于这种简单易用的特性，现在越来越多的芯片集成了这种通信协议。。

其中CS是控制芯片是否被选中的，也就是说只有片选信号为预先规定的使能信号时（高电位或低电位），对此芯片的操作才有效。这就允许在同一总线上连接多个SPI设备成为可能。接下来就负责通讯的3根线了。SCLK信号线只由主设备控制，从设备不能控制信号线。SPI是串行通讯协议，数据是一位一位的传输的。由SCLK提供时钟脉冲，SDI，SDO则基于此脉冲完成数据传输。数据输出通过 SDO线，数据在时钟上升沿或下降沿时改变，在紧接着的下降沿或上升沿被读取。完成一位数据传输，输入也使用同样原理。这样，在至少8次时钟信号的改变（上沿和下沿为一次），就可以完成8位数据的传输。

SPI还是一个数据交换协议：因为SPI的数据输入和输出线独立，所以允许同时完成数据的输入和输出。不同的SPI设备的实现方式不尽相同，主要是数据改变和采集的时间不同，在时钟信号上沿或下沿采集有不同定义，具体请参考相关器件的文档。

本实践所设计控制器遵循标准通用的SPI Flash控制协议，可实现多个厂家的SPI Flash device操作，配套的测试扩展板上的DIP 8插座可插上不同厂家的SPI Flash device; 本实例操作的为Winbond公司的W25xx系列，其端口结构如图所示：

华邦W25xx系列SPI NOR Flash

W25xx的SPI接口由8个引脚构成：/CS，DO，/WP，GND，VCC，/HOLD，CLK及DIO，其中GND和VCC是电源端，而CLK是整个SPI总线的时钟， DIO是主机的输出，从机的输入，DO 是主机的输入，从机的输出。/CS是从机的选择标志端口，在互相通信的两个SPI总线的器件，/CS 由主机控制，当/CS为低电平时，主机与从机开始交互信息。/WP为FLASH状态保护端口，当/WP为低电平时，FLASH部分状态位无法改变，这样可以间接对FLASH memory中的数据起到保护作用，防止外来数据的写入而造成原有数据的丢失。本实例通过对最基本的Flash 器件和SPI总线协议的研究和实现，设计了SPI Flash Controller, 以此来熟悉IP核的设计和验证。

2 设计规格

l Support AMBA4 AXI(lite) 32 bit Bus interface.

l Support SPI flash 1 bit interface.

l Support SPI mode 0 and SPI mode 3 programable

l Support 4 byte read/write buffer.

l Support the following instruction: Write Enable/Disable, Read/Write Status Register, Read Data, Fast Read, Page Program, Block/Sector/Chip Erase, Read JEDEC ID.

l Support write buffer before starting write_opeartion to device.

l Support buffer empty/full interrupt.

l Support transfer complete interrupt.

l Support buffer empty/full and transfer complete status polling.

l Support interrupt status write "1" clear.

l Support interrupt enable/disable/programable.

l Support system clock frequency 25MHz to 100MHz.

l Support SPI interface transfer speed configurable: 1/4 system clock, 1/8 system clock, 1/16 system clock.

l Support software reset.

3 I/O Ports Description

3.1 Global signal

Name

Direction

Width

Description

SYSCLK

Input

1

Global Clock Input

25 -100Mhz

RST_B

Input

1

Global Asynchronous Reset Input

Low active.

3.2 AXI Interface

Name	Direction	Width	Description
AWVALID	Input	1	Write Address Valid This signal indicates that valid write address and control information are available..
AWREADY	Output	1	Write Address Ready This signal indicates that the slave is ready to accept an address and associated control signals..
AWADDR	Input	32	Write Address The write address bus gives the address of the first transfer in a writer burst transaction.
AWPROT	Input	3	Protect type This signal indicates the normal, priviledged, or secure protection level of the transaction and whether the transaction.
WVALID	Input	1	Write Valid This signal indicates that valid write data and strobes are available.
WREADY	Output	1	Write Ready This signal indicates that slave can accept the write data.
WDATA	Input	32	Write Data The write data bus is 32 bit wide.
WSTRB	Input	4	Write strobes This signal indicates which bytes lanes to update in memory.
BVALID	Output	1	Write Response Valid This signal indicates that a valid write response is available.
BREADY	Input	1	Write Response Ready This signal indicates that the master can accept the response information.
BRESP	Output	2	Write Response This signal the status of the write transaction.
ARVALID	Input	1	Read Address Valid This signal indicates, when HIGH, that read address and control information is valid and will remain stable until the address acknowledge signal, ARREADY, is high
ARREADY	Output	1	Read Address Ready This siganl indicates that the slave is ready to accept an address and associated control signal.
ARADDR	Input	32	Read Address The read address bus gives the initial address of a read burst transaction.
ARPORT	Input	3	Protect type This signal indicates the normal,priviledged, or secure protetion level of the transaction and whether the transaction is a data access or an instruction access.
RVALID	Output	1	Read Valid This signal indicates that the required read data is available and the read transfer can complete.
RREADY	Input	1	Read Ready This signal indicates that the master can accept the read data and response information.
RDATA	Output	32	Read Data This read data bus is 32 bit wide.
RRESP	Output	2	Read Response This signal indicates the status of the read transaction.

3.3 SPI Interface

Name	Direction	Width	Description
SPI_CLK	Output	1	SPI Serial Clock Serial Clock for SPI Flash
SPI_DI	Input	1	Serial Data Input Serial Data Output for SPI Flash
SPI_DO	Output	1	Serial Data Input Serial Data Input for SPI Flash
SPI_CS_B	Output	1	SPI Chip Select Chip Enable for SPI Flash.Low active to indicate that the SPI Flash is selected.

3.4 Interrupt

Name

Direction

Width

Description

SPI_INT

Output

1

SPI Interrupt

SPI Flash controller interrupt signal, high active

4 Registers File

Register Lists

Address	Name	Access	Description
32'h0	SPI_CON	RW	SPI Configuration Register .
32'h4	SPI_MODE	RW	SPI Mode Configuration Register.
32'h8	SPI_CMD	RW	SPI Flash Operation Command and Address.
32'hc	INT_FLAG	RW	The Interrupt Status Register
32'h10	INT_MASK	RW	The Interrupt Mask Register.
32'h14	W_DATA	RW	Transfer Data. Data from CPU.
32'h18	R_DATA	RW	Receive Data. Data from SPI Flash.
32'h1c	BYTE_NUM	RW	Indicate Write/Read Bytes.

4.1 SPI Configuration Register (SPI_CON,ADDR=32'h0)

Default value: 32’h00

Register Bits	Access	Function Description
0	STR	Start FLAG High active to indicate start an operation.
1	WR	Write/Read FLAG This bit indicate write or read operation. 0: Write Flash; 1: Read Flash;
2	RST_SW	Software Reset FLAG High active to indicate software reset Flash.
31:3	Reserved	Reserved

4.2 SPI Mode Configuration Register(SPI_MODE,ADDR=32'h4)

Default value: 32’h0

Register Bits	Access	Function Description
0	SPI_MODE	SPI Flash Work Mode This bit indicate the work mode of Flash. 0: mode 0; 1: mode 3;
2:1	CLK_MODE	Clock Mode This bits indicate the Clock mode of Flash. 00:1/4 system clock 01:1/8 system clock 10:1/16 system clock 11:Reserved
31:3	Reserved	Reserved

4.3 SPI Flash Command and Address (SPI_CMD,ADDR=32'h8)

Default value: 32’h0

Register Bits	Access	Function Description
7:0	CMD	Command Code The SPI Flash control operation code.
15:8	ADDR_H	The High 8 bits address The high 8 bits address to indicate the start of W/R into the flash.
23:16	ADDR_M	The Middle 8 bits address The middle 8 bits address to indicate the start of W/R into the flash.
31:24	ADDR_L	The Low 8 bits address The low 8 bits address to indicate the start of W/R into the flash.

4.4 Interrupt Status Register (INT_FLAG,ADDR=32'hc)

Default value: 32’h0

Register Bits	Access	Function Description
0	CMP_FLAG	Transfer complete Flag, Write 1 Clear High active to indicate transfer complete state.
1	T_EMP_FLAG	Transfer FIFO Empty Flag, Write 1 Clear High active to indicate transfer FIFO empty state.
2	T_FUL_FLAG	Transfer FIFO Full Flag, Write 1 Clear High active to indicate transfer FIFO full state.
3	R_EMP_FLAG	Receive FIFO Empty Flag, Write 1 Clear High active to indicate receive FIFO empty state.
4	R_FUL_FLAG	Receive FIFO Full Flag, Write 1 Clear High active to indicate receive FIFO full state.
31:3	Reserved	Reserved

4.5 Interrupt Mask Register (INT_MASK,ADDR=32'h10)

Default value: 32’h0

Register Bits	Access	Function Description
0	CMP_MASK	Mask of Transfer complete Flag High active.
1	T_EMP_MASK	Mask of Transfer FIFO Empty Flag High active.
2	T_FUL_MASK	Mask of Transfer FIFO Full Flag High active.
3	R_EMP_MASK	Mask of Receive FIFO Empty Flag High active .
4	R_FUL_MASK	Mask of Receive FIFO Full Flag High active.
30:5	Reserved	Reserved
31	GLO_MASK	Global Mask

4.6 WRITE DATA (W_DATA,ADDR=32'h14)

Default value: 32’h0

Register Bits

Access

Function Description

31:0

W_DATA

Save the Data from CPU

32 bits.

4.7 Read Data FIFO (R_DATA,ADDR=32'h18)

Default value: 32’h0

Register Bits

Access

Function Description

31:0

R_DATA

Save the Data from SPI Flash

32 bits.

4.8 BYTE _NUM (ADDR=32'h1c)

Default value: 32’h1

Register Bits

Access

Function Description

15:0

BYTE_NUM

BYTE COUNT

Indicate the bytes of data R/W.

31:16

Reserved

5 Functional Description

5.1 SPI Flash Controller Block Diagram

The FSM is used to control and harmonize the whole system. Master configures the necessary information to the controller through AXI Bus

FSM: Control the configuration logic, make the whole system to work normally.

Register File: Store the configure, status and data.

FIFO: Used as a buffer in RECEIVER and TRANSMITTER.

Interface : Translate the logic

5.2 Internal FSM

Current State	Function	Next Status	Jump Condition
IDLE	Wait start signal	T_CMD	STR = 1
IDLE	Wait start signal	IDLE	STR = 0 or Reset not end
T_CMD	Transfer Command	T_ADDR_H	T_count = 8
		T_DATA	The command is 9FH
		IDLE	The commnd is 06H\|04H\| C7H/60H
T_ADDR_H	Transfer the address high 8 bits.	T_ADDR_M	T_count = 8
T_ADDR_M	Transfer the address middle 8 bits.	T_ADDR_L	T_count = 8
T_ADDR_L	Transfer the address low 8 bits	IDLE	CMD is D8H\|52H\|20H
T_ADDR_L	Transfer the address low 8 bits	T_DATA	T_count = 8
T_DATA	Transfer data	T_DATA	Transfer data not end
T_DATA	Transfer data	IDLE	Transfer data end

5.3 FIFO

FIFO is important to this design as all data are transferred by it. Following is the 2-pointer FIFO.

It is a 8*8-bit FIFO, so the width of both write pointer (WP) and read pointer (RP) are 3 bits. Read data once, RP adds one, while write data once, WP adds one. When write, first write data, then move the WP pointer; when read, first read data, then move the RP pointer.

When WP = RP indicates FIFO is empty.

When WP[2] = (~RP[2]) and WP[1:0] = RP[1:0] shows this is a full FIFO.

When FIFO is full/empty but still write/read, FIFO will overflow/underflow.

5.4 Polling Status and Interrupt

The design provide programmable interrupt output and polling the interrupt flag through INT_FLAG. SPI_INT will be high when interrupt happens.

Each interrupt source can read in proper bits of INT_FLAG.

Each interrupt source can also be mask in the same bits of INT_MASK.

Each interrupt should be clear by sending clear interrupt command.

There are such interrupt source as below:

Interrupt source	Description	Mask bit
CMP_FLAG	Transfer Complete	0
T_EMP_FLAG	Transfer FIFO Empty Flag	1
T_FUL_FLAG	Transfer FIFO Full Flag	2
R_EMP_FLAG	Receive FIFO Empty Flag	3
R_FUL_FLAG	Receive FIFO Full Flag	4

6 Timing Figures

6.1 AXI Bus Write

6.2 AXI Bus Read

6.3 SPI Bus Write

6.4 SPI Bus Read

6.5 SPI Clock

6.6 Parallel to Serial

6.7 Serial to Parallel

7 SOC 整合实现

7.1 SPI FLASH 控制器IP设计实验项目的硬件平台实现

SPI FLASH控制器IP核设计是AMBA AXI slave 32bit总线接口，而我们FBIO Wrapper是AMBA AXI 64bit总线接口, 不能直接连接在一起，需要一个axi64_to_axi32的Bridge进行连接，如下；如下图所示：

本实验以Plus1 7021实践平台配套的FPGA子板和扩展测试板完成相关实验，FPGA子板的开发工具采用XILINX的Vivado集成开发环境(版本号为2018.3);为了方便将用户自己需要验证的IP方便连接到SOC系统中验证，本实验提供了相应的设计参考基础文件，如下

设计案例与SP7021主板与FPGA子板脚位对应连接关系如下表所示：

1: 主板上的U20B接FPGA子板的J2(Pin脚对应，如 1-51...),提供主板上的Plus1 主芯片与FPGA的数据传输通道

Design Demo	FPGA子板			SP7021主板
spi_flash_axi	J2		U1E	U20B
Top Port Name	Schematic Name		FPGA I/O	Schematic Name
	1	GND		51	GND
	2	GND		52	GND
FPGA_PAD[0]	3	B34_L24_N	T8	53	FBIO_PAD_0
FPGA_PAD[43]	4	B34_L24_P	R8	54	FBIO_PAD_1
	5	VIN		55	VCC(3.3V)
	6	VCCIO34		56	VCC(3.3V)
FPGA_PAD[1]	7	B34_L21_N	V9	57	FBIO_PAD_2
FPGA_PAD[42]	8	B34_L21_P	U9	58	FBIO_PAD_3
FPGA_PAD[2]	9	B34_L18_N	N6	59	FBIO_PAD_4
FPGA_PAD[41]	10	B34_L18_P	M6	60	FBIO_PAD_5
FPGA_PAD[3]	11	B34_L22_N	U6	61	FBIO_PAD_6
FPGA_PAD[40]	12	B34_L22_P	U7	62	FBIO_PAD_7
FPGA_PAD[4]	13	B34_L20_N	V6	63	FBIO_PAD_8
FPGA_PAD[39]	14	B34_L20_P	V7	64	FBIO_PAD_9
FPGA_PAD[5]	15	B34_L23_N	T6	65	FBIO_PAD_10
FPGA_PAD[38]	16	B34_L23_P	R7	66	FBIO_PAD_11
FPGA_PAD[6]	17	B34_L10_N	V4	67	FBIO_PAD_12
FPGA_PAD[37]	18	B34_L10_P	V5	68	FBIO_PAD_13
FPGA_PAD[7]	19	B34_L19_P	R6	69	FBIO_PAD_14
FPGA_PAD[36]	20	B34_L19_N	R5	70	FBIO_PAD_15
FPGA_PAD[8]	21	B34_L8_P	U4	71	FBIO_PAD_16
FPGA_PAD[35]	22	B34_L8_N	U3	72	FBIO_TCLK
FPGA_PAD[9]	23	B34_L9_N	V2	73	FBIO_RCLK
FPGA_PAD[34]	24	B34_L9_P	U2	74	FBIO_PAD_17
FPGA_PAD[10]	25	B34_L7_N	V1	75	FBIO_PAD_18
FPGA_PAD[33]	26	B34_L7_P	U1	76	FBIO_PAD_19
FPGA_PAD[11]	27	B34_L13_P	N5	77	FBIO_PAD_20
FPGA_PAD[32]	28	B34_L13_N	P5	78	FBIO_PAD_21
FPGA_PAD[12]	29	B34_L12_P	T5	79	FBIO_PAD_22
FPGA_PAD[31]	30	B34_L12_N	T4	80	FBIO_PAD_23
FPGA_PAD[13]	31	B34_L11_N	T3	81	FBIO_PAD_24
FPGA_PAD[30]	32	B34_L11_P	R3	82	FBIO_PAD_25
FPGA_PAD[29]	33	B34_L14_P	P4	83	FBIO_PAD_26
FPGA_PAD[28]	34	B34_L14_N	P3	84	FBIO_PAD_27
FPGA_PAD[14]	35	B34_L16_N	N4	85	FBIO_PAD_28
FPGA_PAD[27]	36	B34_L16_P	M4	86	FBIO_PAD_29
FPGA_PAD[15]	37	B34_L17_N	T1	87	FBIO_PAD_30
FPGA_PAD[26]	38	B34_L17_P	R1	88	FBIO_PAD_31
FPGA_PAD[16]	39	B34_L15_N	R2	89	FBIO_PAD_32
FPGA_PAD[25]	40	B34_L15_P	P2	90	FBIO_PAD_33
FPGA_PAD[17]	41	B34_L3_N	N1	91	FBIO_PAD_34
FPGA_PAD[24]	42	B34_L3_P	N2	92	FBIO_PAD_35
FPGA_PAD[18]	43	B34_L1_N	M1	93	FBIO_PAD_RSTB
FPGA_PAD[23]	44	B34_L1_P	L1	94	EXT0_INT
	45	VCCIO34		95	VCC(3.3V)
	46	VIN		96	VCC(3.3V)
FPGA_PAD[19]	47	B34_L4_P	M3	97	EXT1_INT
FPGA_PAD[20]	48	B34_L4_N	M2	98
	49	GND		99	GND
	50	GND		100	GND

2: 主板上的U20A接FPGA子板的J1(Pin脚以一对应，如 1-1...)，经由J17将FPGA Bank 35的42 pin IO(3.3v) 扩展出来，供用户使用;本实验案例中接测试扩展板的J2(Pin脚以一对应，如 1-1...),提供FPGA的IO扩展

Design Demo	FPGA子板			SP7021主板				测试扩展板
spi_flash_axi	J1		U1F	U20A		J17		J2
Top Port Name	Schematic Name		FPGA I/O	Schematic Name		Schematic Name		Schematic Name
	1	GND		1	GND
	2	GND		2	GND
	3	B35_L23_N	K1	3	B35_L23_N	5	B35_L23_N	5	PMOD8
	4	B35_L23_P	K2	4	B35_L23_P	6	B35_L23_P	6	PMOD7
	5	VIN		5	VIN
	6	VCCIO35		6	VCCIO35
	7	B35_L15_N	G2	7	B35_L15_N	7	B35_L15_N	7	PMOD6
	8	B35_L15_P	H2	8	B35_L15_P	8	B35_L15_P	8	PMOD5
	9	B35_L13_N	F3	9	B35_L13_N	9	B35_L13_N	9	PMOD4
	10	B35_L13_P	F4	10	B35_L13_P	10	B35_L13_P	10	PMOD3
	11	B35_L12_N	D3	11	B35_L12_N	11	B35_L12_N	11	LED_D1
	12	B35_L12_P	E3	12	B35_L12_P	12	B35_L12_P	12	PMOD1
	13	B35_L22_P	J3	13	B35_L22_P	13	B35_L22_P	13	LED_D2
	14	B35_L22_N	J2	14	B35_L22_N	14	B35_L22_N	14	PMOD2
	15	B35_L17_N	G1	15	B35_L17_N	15	B35_L17_N	15	LED_D3
	16	B35_L17_P	H1	16	B35_L17_P	16	B35_L17_P	16	LED_D4
	17	B35_L18_N	E1	17	B35_L18_N	17	B35_L18_N	17	LED_D5
	18	B35_L18_P	F1	18	B35_L18_P	18	B35_L18_P	18	LED_D6
	19	B35_L14_N	D2	19	B35_L14_N	19	B35_L14_N	19	LED_D7
	20	B35_L14_P	E2	20	B35_L14_P	20	B35_L14_P	20	LED_D8
	21	B35_L16_P	C2	21	B35_L16_P	21	B35_L16_P	21	SPI_WP
FPGA_SPI_DI	22	B35_L16_N	C1	22	B35_L16_N	22	B35_L16_N	22	SPI_DO
FPGA_SPI_CS_B	23	B35_L9_N	A1	23	B35_L9_N	23	B35_L9_N	23	SPI_CS
	24	B35_L9_P	B1	24	B35_L9_P	24	B35_L9_P	24	SPI_HOLD
FPGA_SPI_CLK	25	B35_L10_P	B3	25	B35_L10_P	25	B35_L10_P	25	SPI_CLK
FPGA_SPI_DO	26	B35_L10_N	B2	26	B35_L10_N	26	B35_L10_N	26	SPI_DI
	27	B35_L8_N	A3	27	B35_L8_N	27	B35_L8_N	27	U1-1
	28	B35_L8_P	A4	28	B35_L8_P	28	B35_L8_P	28	U2-1
	29	B35_L11_N	D4	29	B35_L11_N	29	B35_L11_N	29	U3-1
	30	B35_L11_P	D5	30	B35_L11_P	30	B35_L11_P	30	U4-1
	31	B35_L3_N	A5	31	B35_L3_N	31	B35_L3_N	31	LED-B
	32	B35_L3_P	A6	32	B35_L3_P	32	B35_L3_P	32	LED-F
	33	B35_L2_N	B6	33	B35_L2_N	33	B35_L2_N	33	LED-A
	34	B35_L2_P	B7	34	B35_L2_P	34	B35_L2_P	34	LED-E
	35	B35_L7_N	B4	35	B35_L7_N	35	B35_L7_N	35	LED-D
	36	B35_L7_P	C4	36	B35_L7_P	36	B35_L7_P	36	LED-RA
	37	B35_L1_N	C5	37	B35_L1_N	37	B35_L1_N	37	LED-C
	38	B35_L1_P	C6	38	B35_L1_P	38	B35_L1_P	38	LED-G
	39	B35_L5_N	E5	39	B35_L5_N	39	B35_L5_N
	40	B35_L5_P	E6	40	B35_L5_P	40	B35_L5_P
	41	B35_L6_N	D7	41	B35_L6_N	41	B35_L6_N
	42	B35_L6_P	E7	42	B35_L6_P	42	B35_L6_P
	43	B35_L19_P	G6	43	B35_L19_P	43	B35_L19_P
	44	B35_L19_N	F6	44	B35_L19_N	44	B35_L19_N
	45	VCCIO35		45	VCCIO35
	46	VIN		46	VIN
	47	B35_L4_N	C7	47	B35_L4_N	45	B35_L4_N
	48	B35_L4_P	D8	48	B35_L4_P	46	B35_L4_P
	49	GND		49	GND
	50	GND		50	GND

7.2 SPI FLASH 控制器IP设计实验项目的系统软件平台实现

在IDE 环境中如下图所示，选择sp7021工程名，单击鼠标右键在弹出的菜单中选Copy

接下来再次选择sp7021工程名

单击鼠标右键在弹出的菜单中选Paste,出现下图

在Project name框中填写spi_flash_axi,完成spi_flash_axi 工程名及目录建立，如下图所示

接下来需要复制安装目录\SP7021\example\spi_flash_axi下的所有文件及文件夹到上面建好的spi_flash_axi工程目录中(路径为：安装目录 \SP7021\workspace\spi_flash_axi\),同名文件选择覆盖，这样SPI Flash控制器 IP设计实践所需的程序代码main.c；spi.c；spi.h分别放到如下的路径中:

1）安装目录 \SP7021\workspace\ spi_flash_axi \ 文件夹下的main.c

2）安装目录 \SP7021\workspace\ spi_flash_axi \testapi\util 文件夹下的spi.c

3）安装目录 \SP7021\workspace\ spi_flash_axi \ include\util文件夹下的spi.h

最后按下图所示，鼠标选中红框1，接着点击鼠标右键出现下拉菜单，然后选中红框2，对刚才复制动作做刷新，这样刚才复制的文件就能在IDE环境中显示出来

main.c

void operation_done()

void flash_device_write_en()

void flash_device_done()

void spi_read_id()

void spi_write_data()

void spi_read_data()

int main(void)

{

printf("Build @%s, %s\n", __DATE__, __TIME__);

hw_init();

sys_init();

fbio_init();

disp_hdmi_init();

sp_interrupt_setup(); /* interrupt manager module init */

spi_read_id();

spi_write_data();

spi_read_data();

printf("%s:%5d\n", __FUNCTION__,__LINE__);

while(1);

}

对比数码管控制IP实验，增加了spi flash操作控制相关的函数，用来完成对spi flash读写及擦除操作，如下讲解。

void spi_read_id()

{

spi_reg->SPI_CMD=0x9f;

spi_reg->SPI_CON=0x3;

operation_done();

temp=spi_reg->R_DATA;

printf("@spi flash device id [%x]\n", temp);

}

实现读取flash JEDEC ID的操作，如下：

spi_reg->SPI_CMD=0x9f; 设置读JEDEC ID的命令码9f;

spi_reg->SPI_CON=0x3;启动读JEDEC ID的操作；

operation_done(); 等待本次操作完成；

temp=spi_reg->R_DATA; 从RX FIFO里取出读JEDEC ID操作完成后的结果，并打印出；

void spi_write_data()

{

/////////sector erase///////////////

flash_device_write_en();

spi_reg->SPI_CMD=0x3020;

spi_reg->SPI_CON=0x1;

operation_done();

flash_device_done();

//////////write data///////////////////////////

flash_device_write_en();

spi_reg->BYTE_NUM=0x8;

spi_reg->W_DATA =0x12345678;

spi_reg->W_DATA =0xabcdef91;

spi_reg->SPI_CMD=0x3002;

spi_reg->SPI_CON=0x1;

operation_done();

flash_device_done();

}

实现写数据到flash device的操作，写数据操作必须先对存储数据的地址空间做擦除，然后才能写入数据，如下:

flash_device_write_en(); 对flash 的擦除，写操作之前必需写使能，通过设置命令码06实现；

spi_reg->SPI_CMD=0x3020; 擦除flash 从0x300000地址开始的4k byte空间，通过设置命令码20实现

flash_device_done();等待擦除flash 从0x300000地址开始的4k byte空间，直到操作完成；

spi_reg->BYTE_NUM=0x8;设置写数据到flash device的数目，共8byte;

spi_reg->W_DATA =0x12345678; spi_reg->W_DATA =0xabcdef91;

设置需要写到flash device的数据

spi_reg->SPI_CMD=0x3002;设置flash 从0x300000地址开始的4k byte空间为写数据空间；通过设置命令码02实现

spi_reg->SPI_CON=0x1; 使能写数据操作；

operation_done();

flash_device_done();

等待写8byte数据到flash device,直到操作完成

void spi_read_data()

{

spi_reg->BYTE_NUM=0x8;

spi_reg->SPI_CMD=0x3003;

spi_reg->SPI_CON=0x3;

operation_done();

temp= spi_reg->R_DATA;

printf("Read SPI Flash: [%x]\n", temp);

temp= spi_reg->R_DATA;

printf("Read SPI Flash: [%x]\n", temp);

}

spi_reg->BYTE_NUM=0x8; 设置从flash device读数据的数目，共8byte;

spi_reg->SPI_CMD=0x3003; 设置flash 从0x300000地址开始读数据，通过设置命令码03实现

spi_reg->SPI_CON=0x3; 使能读数据操作；

operation_done();等待从flash device读8byte数据,直到操作完成

程序代码运行

在Plus1 IDE环境中compile后，下载到平台，在terminal窗口看到如下信息

SPI FLASH 控制器IP设计

1 设计简介

2 设计规格

3 I/O Ports Description

3.1 Global signal

3.2 AXI Interface

3.3 SPI Interface

3.4 Interrupt

4 Registers File

Register Lists

4.1 SPI Configuration Register (SPI_CON,ADDR=32'h0)

4.2 SPI Mode Configuration Register(SPI_MODE,ADDR=32'h4)

4.3 SPI Flash Command and Address (SPI_CMD,ADDR=32'h8)

4.4 Interrupt Status Register (INT_FLAG,ADDR=32'hc)

4.5 Interrupt Mask Register (INT_MASK,ADDR=32'h10)

4.6 WRITE DATA (W_DATA,ADDR=32'h14)

4.7 Read Data FIFO (R_DATA,ADDR=32'h18)

4.8 BYTE _NUM (ADDR=32'h1c)

5 Functional Description

5.1 SPI Flash Controller Block Diagram

5.2 Internal FSM

5.3 FIFO

5.4 Polling Status and Interrupt

6 Timing Figures

6.2 AXI Bus Read

6.3 SPI Bus Write

6.4 SPI Bus Read

6.5 SPI Clock

6.7 Serial to Parallel

7 SOC 整合实现

程序代码运行

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