SPI 功能使用方法
Application Note
SPI 功能使用方法
1
適用產品：SM59R16A2 / SM59R08A2
2
SPI 使用概述：
SPI通信使用4個引腳，分別為
z SPI_MOSI: 當master時資料輸出；當slave時資料輸入
z SPI_MISO: 當master時資料輸入；當slave時資料輸出
z SPI_SCK: SPI的時脈信號由master主控產生；資料 (輸出及輸入) 和時脈同步
z SPI_SS:
此引腳功能唯有當作slave mode時可使用（master mode此引腳則當做GPIO使用）
= 0: master致能slave
= 1: master禁能slave
Master
Slave 2
Slave 1
MOSI
MISO
CLK
IO
IO
MOSI
MISO
CLK
MOSI
MISO
CLK
SS
SS
Fig. 15-1: SPI signals between master and slave devices
3
以下說明與 SPI 相關的特殊控制暫存器及特殊狀態暫存器
Special Function Register (SFR)
SPI
SPIC1
SPIC2
SPIS
SPITXD
SPIRXD
Description
Direct
Bit 7
SPI control register 1
SPI control register 2
F1h
F2h
F5h
SPIEN
SPI status register
SPI transmit data
buffer
SPI receive data
buffer
SPIFD
-
Bit 6
Bit 5
Bit 4
SPI function
SPIMSS
SPISSP
SPICKP
TBC[2:0]
SPIMLS
SPIOV
SPITXIF
Bit 3
Bit 2
Bit 1
SPICKE
SPIBR[2:0]
-
RBC[2:0]
SPITDR
SPIRXIF
SPIRDR
Bit 0
RESET
SPIRS
08h
00h
40h
F3h
SPITXD[7:0]
00h
F4h
SPIRXD[7:0]
00h
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
1
Ver A 2008/05
SPI 功能使用方法
Application Note
Mnemonic: SPIC1
7
6
5
SPIEN SPIMSS SPISSP
4
SPICKP
Address: F1h
3
2
1
0
SPICKE
SPIBR[2:0]
Reset
08h
SPIEN: SPI 模主致能旗標：
“1” – 致能
“0” – 禁能
SPIMSS: 主從模式選擇旗標（Master or Slave mode Select）
“1” – MCU 做為 Master mode.
“0” – MCU 做為 Slave mode.
SPISSP: (SS)引腳致能狀態旗標；當 MCU 為 slave 時，可由旗標設定 Slave Select (SS)引腳致能狀態
(slave mode used only)
“1” – 高準位致能 high active.
“0” – 低準位致能 low active.
SPICKP: 時脈閒置準位旗標(master mode used only)
“1” – 時脈閒置時為高準位(SCK high during idle), Ex :
“0” – 時脈閒置時為低準位(SCK high during idle), Ex :
SPICKE: 時脈取樣旗標 Clock sample edge select.
“1” – 正緣取樣 data latch in rising edge
“0” – 負緣取樣 data latch in falling edge.
* 為確保資料取樣的正確性，無論使用正緣或負緣取樣，時脈及資料同步時皆需有足夠的準備時間
(set-up time)及保持時間(hold time)，SM59R16A2/SM59R08A2 時序產生如下圖：
sufficient set-up time
sufficient hold time
SPIBR[2:0]: SPI 鮑率選擇(master mode used only), Fosc 為晶振頻率：
SPIBR[2:0] Baud rate
0:0:0
Fosc/4
0:0:1
Fosc/8
0:1:0
Fosc/16
0:1:1
Fosc/32
1:0:0
Fosc/64
1:0:1
Fosc/128
1:1:0
Fosc/256
1:1:1
Fosc/512
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
2
Ver A 2008/05
SPI 功能使用方法
Application Note
Mnemonic: SPIC2
7
6
5
SPIFD
TBC[2:0]
4
3
-
2
1
RBC[2:0]
Address: F2h
0
Reset
00h
SPIFD: 全雙工模式旗標(Full-duplex mode enable)
“1” : 全雙工模式致能
“0” : 全雙工模式禁能
當全雙工模式旗標”SPIFD”致能時，TBC[2:0]和 RBC[2:0]會被清除並保持為零，即 SPI 全雙工模式
僅允許 8 位元通訊．
Input Shift register
SPIRXD
Output Shift register
SPITXD
Clock Generator
MISO
MISO
MOSI
MOSI
SCK
SCK
SyncMOS Master
Output Shift register
SPITXD
Input Shift register
SPIRXD
SyncMOS Slave
TBC[2:0]: SPI 傳送元位旗標（全雙工模式僅允許 8 位元通訊）
TBC[2:0]
Bit counter
0:0:0
8 bits output
0:0:1
1 bit output
0:1:0
2 bits output
0:1:1
3 bits output
1:0:0
4 bits output
1:0:1
5 bits output
1:1:0
6 bits output
1:1:1
7 bits output
RBC[2:0]: SPI 接收元位旗標（全雙工模式僅允許 8 位元通訊）
RBC[2:0]
Bit counter
0:0:0
8 bits input
0:0:1
1 bit input
0:1:0
2 bits input
0:1:1
3 bits input
1:0:0
4 bits input
1:0:1
5 bits input
1:1:0
6 bits input
1:1:1
7 bits input
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
3
Ver A 2008/05
SPI 功能使用方法
Application Note
Mnemonic: SPIS
7
6
5
SPIMLS SPIOV
4
SPITXIF
3
SPITDR
2
SPIRXIF
Address: F5h
0
Reset
SPIRS
40h
1
SPIRDR
SPIMLS: MSB or LSB output /input first
“1” : 最高位元優先 (MSB output/input first)
“0” : 最低位元優先 (LSB output/input first)
SPIOV: 溢位旗標(Overflow flag)
“1” : 當 SPIRDR 已設定（SPIRXD 原有資料未被讀取）且下一筆資料正寫入 SPIRXD 時，SPIOV
將被設定為”1”，告知 SPIRXD 資料以有損毀．
“0” : 當 SPIRDR 清為零時，SPIOV 則由硬體清除．
SPITXIF: Transmit Interrupt Flag.
“1” : 當 SPITXD 的資料已載入移位暫存器
“0” : 傳送資料完成後必須由軟體清除。
SPITDR: Transmit Data Ready.
“1”: 當程序為傳送模式時，資料儲存至 SPITXD 後，由軟體設定此旗標為”1” 告知 SPI module 可
傳出資料
“0”: 當SPI module由SPITXD完成傳送時或SPITXD被載至移位暫存器時，此旗標則由硬體自動清除
SPIRXIF: Receive Interrupt Flag.
“1” : 當 SPIRXD 被載入新一筆資料後
“0” : 接收資料完成後必須由軟體清除。
SPIRDR: Receive Data Ready.
“1” : SPI module接收資料時，SPIRDR由硬體自動設定為”1”，以告知MCU完成接收並儲存至
SPIRXD；當新的一筆資料寫入SPIRXD，而SPIRDR未清除時，SPIRXD原有的資料將被覆寫，產
生overflow
“0” : 由SPIRXD讀取資料後，必須由軟體清除此旗標
SPIRS: Receive Start.
“1” : 告知 SPI 模組可由 SPIRXD 接收資料
Mnemonic: SPITXD
7
6
5
4
3
SPITXD[7:0]
2
1
0
Address: F3h
Reset
00h
SPITXD[7:0]: 傳送資料緩衝器.
Mnemonic: SPIRXD
7
6
5
4
3
SPIRXD[7:0]
2
1
Address: F4h
0
Reset
00h
SPIRXD[7:0]: 接收資料緩衝器
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
4
Ver A 2008/05
SPI 功能使用方法
Application Note
4
以下為 SPI 相對應的中斷向量表，和中斷有關的致能旗標
Table 11-1: Interrupt vectors
IE0 – External interrupt 0
TF0 – Timer 0 interrupt
Interrupt Vector
Address
0003h
000Bh
Interrupt Number
*(use Keil C Tool)
0
1
IE1 – External interrupt 1
0013h
2
TF1 – Timer 1 interrupt
RI0/TI0 – Serial channel 0 interrupt
TF2/EXF2 – Timer 2 interrupt
001Bh
0023h
002Bh
3
4
5
SPIIF – SPI interrupt
004Bh
9
ADCIF – A/D converter interrupt
EEIIF – Expanded External Interrupt
IICIF – IIC interrupt
RI1/TI1 – Serial channel 1 interrupt
0053h
005Bh
006Bh
0083h
10
11
13
16
Interrupt Request Flags
*See Keil C about C51 User’s Guide about Interrupt Function description
Mnemonic
IEN0
IEN1
IEN2
IP0
IP1
Description
Interrupt Enable
0 register
Interrupt Enable
1 register
Interrupt Enable
2 register
Interrupt priority
level 0
Interrupt priority
level 1
Direct
Bit 7
Bit 6
Bit 5
Interrupt
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
RESET
A8h
EA
-
ET2
ES0
ET1
EX1
ET0
EX0
00h
B8h
EXEN2
-
IEIIC
-
IEEEI
IEADC
IESPI
-
00h
9Ah
-
-
-
-
-
-
-
ES1
00h
A9h
-
-
IP0.5
IP0.4
IP0.3
IP0.2
IP0.1
IP0.0
00h
B9h
-
-
IP1.5
IP1.4
IP1.3
IP1.2
IP1.1
IP1.0
00h
*如果需要使用中斷程序，可參考以下設置：
(1) SPI 中斷致能設罝：
IEN0 |= 0x80;
//Enable interrupt All
IEN1 |= 0x02;
//Enable interrupt SPI
(2) SPI 中斷程序表示：
void SPI_interrupt(void) interrupt 13 using 1
{
IRCON_SPIIF = 0;
//Clear interrupt flag
}
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
5
Ver A 2008/05
SPI 功能使用方法
Application Note
5
以下為兩顆 MCU 分別當做 SPI master 及 slave 通訊的流程圖
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
6
Ver A 2008/05
SPI 功能使用方法
Application Note
6 SPI master 及 slave 通訊的範例程式
說明：
6.1 Master 將以資料(0xFF~0x00)傳至 Slave
6.2 Slave 接受後，以相同的資料回傳給 Master
6.3 Master 接受 Slave 回傳的資料後，將該資料與原傳出資料比較，相同則表示通訊正確，不相同
則反之
Description
Main program
Master:
//====================================================================
//
//
SYNCMOS TECHNOLOGY
//
//====================================================================
#include "..\h\SM59R16A2.h"
#include "..\h\SM59R16A2_extradef.h"
#include "..\LCD\LCD16x2.h"
#include "..\MISC\delay.h"
#define Control_Byte 0xA0
#define SPI_SS
P1_0
#define SPITDR=1
SPIS |= 0x08
/* void SPI_interrupt(void) interrupt 13 using 1
{
IRCON_SPIIF = 0;
//Clear interrupt flag
}*/
void SPI_Init(void)
{
SPIC1 = 0xD8;
//SPIC1 |= 7;
SPIC2 = 0x00;
SPIS = 0x40;
}
//SPI Enable/ master/ NC/ idle hi/ rising latch
//BR=(Fosc/512)
//SPI full-duplex disable /8-bit communicate
//MSB send first
void SPI_TX( unsigned char DATA)
{
SPITXD = DATA;
SPIS
|= 0x08;
while( !(SPIS&SPI_TXIF) );
SPIS
&= (~SPI_TXIF);
}
unsigned char SPI_RX(void)
{
unsigned char Temp;
SPIS
|= 0x01;
while( !(SPIS&SPI_RXIF) );
Temp
= SPIRXD;
SPIS
|= 0x02;
SPIS &= (~SPI_RXIF);
return Temp;
//Load to Buffer
//SPITDR
//TX completed
//Clear TXIF bit
//Receive Start
//RX completed
//Load from Buffer
//Receive Data Ready
//Clear RXIF bit
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
7
Ver A 2008/05
SPI 功能使用方法
Application Note
Description
Main program
Master:
}
void main()
{
unsigned long Err =0, counter =1;
unsigned char TxData, RxData,j;
LCD_Init();
SPI_Init();
Delay10mSec(1);
//must wait for LCD stable
while(1)
{
for(TxData=0xFF; TxData>0; TxData--)
{
PrintLcdStrLX( 1, 0, "M_TX:
PrintLcdStrLX( 2, 0, "M_RX:
SPI_SS = 0;
SPI_TX( TxData );
//for(j=0; j<0; j++);
RxData = SPI_RX();
SPI_SS = 1;
");
");
//CS
//TX
//Dealy time
//RX
//CS
SetCursorAddr(1, 6); PrintLcdHex( TxData );
SetCursorAddr(2, 6); PrintLcdHex( RxData );
counter++;
SetCursorAddr(1, 12);
if(TxData!=RxData)
SetCursorAddr(2, 12);
P2=TxData;
PrintLcdDec( counter );
Err++;
PrintLcdDec( Err );
//result
}
}
}
Description
Main program
Slave:
//====================================================================
//
//
SYNCMOS TECHNOLOGY
//
//====================================================================
#include "..\h\SM59R16A2.h"
#include "..\h\SM59R16A2_extradef.h"
#include "..\LCD\LCD16x2.h"
#include "..\MISC\delay.h"
void SPI_Init(void)
{
SPIC1 =0x98; //SPI Enable/ slave/ Low active / NC / rising latch/ NC NC NC
SPIC2 =0x00; //SPI full-duplex disable /8-bit communicate
SPIS =0x40; //MSB send first
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
8
Ver A 2008/05
SPI 功能使用方法
Application Note
Description
Main program
Slave:
}
void SPI_TX( unsigned char DATA)
{
SPITXD = DATA;
SPIS
|= 0x08;
while( !(SPIS&SPI_TXIF) );
SPIS
&= (~SPI_TXIF);
}
unsigned char SPI_RX(void)
{
unsigned char Temp;
SPIS
|= 0x01;
while( !(SPIS&SPI_RXIF) );
Temp
= SPIRXD;
SPIS
|= 0x02;
SPIS &= (~SPI_RXIF);
return Temp;
}
//Load to Buffer
//SPITDR
//TX completed
//Clear TXIF bit
//Receive Start
//RX completed
//Load from Buffer
//SPIRDR
//Clear RXIF bit
void main()
{
unsigned long Err =0, counter =1;
unsigned char TxData=0, RxData=0,j;
LCD_Init();
SPI_Init();
Delay10mSec(1);
//must wait for LCD stable
while(1)
{
RxData = SPI_RX(); //RX
SPI_TX( RxData ); //TX
P2 = RxData;
//result
}
}
Specifications subject to change without notice, contact your sales representatives for the most recent information.
IRFWX-A079
9
Ver A 2008/05