main.lst

avr 单片机twi源程序 功能：实现TWI主从机通讯.

__text_start:
__start:
    002A E5CF      LDI	R28,0x5F
    002B E0D4      LDI	R29,4
    002C BFCD      OUT	0x3D,R28
    002D BFDE      OUT	0x3E,R29
    002E 51C0      SUBI	R28,0x10
    002F 40D0      SBCI	R29,0
    0030 EA0A      LDI	R16,0xAA
    0031 8308      STD	Y+0,R16
    0032 2400      CLR	R0
    0033 E6E0      LDI	R30,0x60
    0034 E0F0      LDI	R31,0
    0035 E010      LDI	R17,0
    0036 36E0      CPI	R30,0x60
    0037 07F1      CPC	R31,R17
    0038 F011      BEQ	0x003B
    0039 9201      ST	R0,Z+
    003A CFFB      RJMP	0x0036
    003B 8300      STD	Z+0,R16
    003C E5E4      LDI	R30,0x54
    003D E0F0      LDI	R31,0
    003E E6A0      LDI	R26,0x60
    003F E0B0      LDI	R27,0
    0040 E010      LDI	R17,0
    0041 35E4      CPI	R30,0x54
    0042 07F1      CPC	R31,R17
    0043 F021      BEQ	0x0048
    0044 95C8      LPM
    0045 9631      ADIW	R30,1
    0046 920D      ST	R0,X+
    0047 CFF9      RJMP	0x0041
    0048 940E00B0  CALL	_main
_exit:
    004A CFFF      RJMP	_exit
FILE: F:\2007电子设计\古欣\twitest\twi_test\twi.c
(0001) 
(0002) #include "config.h"
(0003) 
(0004) //TWI master initialize
(0005) // bit rate:100
(0006) void twi_master_init(void)
(0007) {
(0008)  TWCR= 0x00; //disable twi
_twi_master_init:
    004B 2422      CLR	R2
    004C BE26      OUT	0x36,R2
(0009)  TWBR= 0x64; //set bit rate
    004D E684      LDI	R24,0x64
    004E B980      OUT	0x00,R24
(0010)  TWSR= 0x00; //set prescale
    004F B821      OUT	0x01,R2
(0011)  TWAR= 0x00; //set slave address
    0050 B822      OUT	0x02,R2
(0012)  TWCR= 0x04; //enable twi
    0051 E084      LDI	R24,4
    0052 BF86      OUT	0x36,R24
    0053 9508      RET
(0013) }
(0014) 
(0015) //TWI slave initialize
(0016) // bit rate:100
(0017) void twi_slave_init(uint8 add)
(0018) {
(0019)  TWCR= 0x00; //disable twi
_twi_slave_init:
  add                  --> R16
    0054 2422      CLR	R2
    0055 BE26      OUT	0x36,R2
(0020)  TWBR= 0x64; //set bit rate
    0056 E684      LDI	R24,0x64
    0057 B980      OUT	0x00,R24
(0021)  TWSR= 0x00; //set prescale
    0058 B821      OUT	0x01,R2
(0022)  TWAR= (add<<1); //set slave address 从机地址为 0x01
    0059 2E20      MOV	R2,R16
    005A 0C22      LSL	R2
    005B B822      OUT	0x02,R2
(0023)  TWCR= (1<<TWEN)|(1<<TWEA)|(1<<TWIE); //enable twi
    005C E485      LDI	R24,0x45
    005D BF86      OUT	0x36,R24
    005E 9508      RET
(0024)  //TWEN必须置位以使能TWI接口。TWEA也要置位以使主机寻址到自己(从机地址或广播) 时返回确认信息ACK
(0025) }
(0026) 
(0027) //总线上起动开始条件
(0028) void i2c_start(void)
(0029) {
(0030) 	TWCR= (1<<TWINT)|(1<<TWSTA)|(1<<TWEN);
_i2c_start:
    005F EA84      LDI	R24,0xA4
    0060 BF86      OUT	0x36,R24
(0031)    	while (!(TWCR & (1<<TWINT))); //等待START 信号成功发送
    0061 B626      IN	R2,0x36
    0062 FE27      SBRS	R2,7
    0063 CFFD      RJMP	0x0061
    0064 9508      RET
(0032) }
(0033) 
(0034) //把一个字节数据输入器件, 返回TWI状态
(0035) //发送地址,r_w：1为读，0为写
(0036) uint8 i2c_write_addr(uint8 addr,uint8 r_w)
(0037) {
(0038)  	if(r_w)
_i2c_write_addr:
  r_w                  --> R18
  addr                 --> R16
    0065 2322      TST	R18
    0066 F021      BEQ	0x006B
(0039) 	{
(0040) 	 TWDR = addr|r_w;     //RW 为1：读操作
    0067 2E20      MOV	R2,R16
    0068 2A22      OR	R2,R18
    0069 B823      OUT	0x03,R2
(0041) 	}
    006A C003      RJMP	0x006E
(0042) 	else
(0043) 	{
(0044) 	TWDR = addr & 0xFE;   // RW 为0: 写操作
    006B 2F80      MOV	R24,R16
    006C 7F8E      ANDI	R24,0xFE
    006D B983      OUT	0x03,R24
(0045) 	} 
(0046) 
(0047)    	TWCR = (1<<TWINT)|(1<<TWEN); 
    006E E884      LDI	R24,0x84
    006F BF86      OUT	0x36,R24
(0048)    	while (!(TWCR & (1<<TWINT)));
    0070 B626      IN	R2,0x36
    0071 FE27      SBRS	R2,7
    0072 CFFD      RJMP	0x0070
(0049)    	_NOP();
    0073 0000      NOP
(0050)    	return(TWSR&0b11111000); //TWSR高五位为I2C工作状态。
    0074 B101      IN	R16,0x01
    0075 7F08      ANDI	R16,0xF8
    0076 9508      RET
(0051) }
(0052) 
(0053) //把一个字节数据输入器件, 返回TWI状态
(0054) //发送数据
(0055) uint8 i2c_write_data(uint8 data)
(0056) {
(0057) 	TWDR = data;
_i2c_write_data:
  data                 --> R16
    0077 B903      OUT	0x03,R16
(0058)    	TWCR = (1<<TWINT)|(1<<TWEN); 
    0078 E884      LDI	R24,0x84
    0079 BF86      OUT	0x36,R24
(0059)    	while (!(TWCR & (1<<TWINT)));
    007A B626      IN	R2,0x36
    007B FE27      SBRS	R2,7
    007C CFFD      RJMP	0x007A
(0060)    	_NOP();
    007D 0000      NOP
(0061)    	return(TWSR&0b11111000); //TWSR高五位为I2C工作状态。
    007E B101      IN	R16,0x01
    007F 7F08      ANDI	R16,0xF8
    0080 9508      RET
(0062) }
(0063) 
(0064) 
(0065) //从器件读出一个字节
(0066) uint8 i2c_read(void)
(0067) {
(0068)    	TWCR = (1<<TWINT)|(1<<TWEN); 
_i2c_read:
    0081 E884      LDI	R24,0x84
    0082 BF86      OUT	0x36,R24
(0069) 	Twi_NoAcK();
    0083 B786      IN	R24,0x36
    0084 708F      ANDI	R24,0xF
    0085 6880      ORI	R24,0x80
    0086 BF86      OUT	0x36,R24
(0070) 	while (!(TWCR & (1<<TWINT)));
    0087 B626      IN	R2,0x36
    0088 FE27      SBRS	R2,7
    0089 CFFD      RJMP	0x0087
(0071)    	return(TWDR);
    008A B103      IN	R16,0x03
    008B 9508      RET
(0072) }
(0073) 
(0074) //总线上起动停止条件 
(0075) void i2c_stop(void) 
(0076) { 
(0077)    TWCR = (1<<TWINT)|(1<<TWSTO)|(1<<TWEN); 
_i2c_stop:
    008C E984      LDI	R24,0x94
    008D BF86      OUT	0x36,R24
    008E 9508      RET
_i2c_maste_transt:
  data                 --> R20
  addr                 --> R22
    008F 940E0153  CALL	push_gset2
    0091 2F42      MOV	R20,R18
    0092 2F60      MOV	R22,R16
(0078) }
(0079) 
(0080) //操作步骤： 启动，发送地址，发送数据，关闭总线
(0081) void i2c_maste_transt(uint8 addr, uint8 data)
(0082) {
(0083)  i2c_start();
    0093 DFCB      RCALL	_i2c_start
(0084)  
(0085)  if(i2c_write_addr(addr, 0)==TW_MT_SLA_ACK) //发送地址成功并收到ACK
    0094 2722      CLR	R18
    0095 2F06      MOV	R16,R22
    0096 DFCE      RCALL	_i2c_write_addr
    0097 3108      CPI	R16,0x18
    0098 F411      BNE	0x009B
(0086)  {
(0087)   i2c_write_data(data);
    0099 2F04      MOV	R16,R20
    009A DFDC      RCALL	_i2c_write_data
(0088)  }
(0089)  i2c_stop();
    009B DFF0      RCALL	_i2c_stop
    009C 940E014A  CALL	pop_gset2
    009E 9508      RET
_i2c_maste_read:
  tmp                  --> R20
  addr                 --> R22
    009F 940E0153  CALL	push_gset2
    00A1 2F60      MOV	R22,R16
(0090) }
(0091) //操作步骤，启动，发送地址，读数据，关闭总线
(0092) uint8 i2c_maste_read(uint8 addr)
(0093) {
(0094)   uint8 tmp=0; 
    00A2 2744      CLR	R20
(0095)   i2c_start();
    00A3 DFBB      RCALL	_i2c_start
(0096)   if(i2c_write_addr(addr, 1)==TW_MR_SLA_ACK) //发送地址成功并收到ACK
    00A4 E021      LDI	R18,1
    00A5 2F06      MOV	R16,R22
    00A6 DFBE      RCALL	_i2c_write_addr
    00A7 3400      CPI	R16,0x40
    00A8 F411      BNE	0x00AB
(0097)   {
(0098)    tmp=i2c_read();
    00A9 DFD7      RCALL	_i2c_read
    00AA 2F40      MOV	R20,R16
(0099)   }
(0100)   i2c_stop();
    00AB DFE0      RCALL	_i2c_stop
(0101)   return tmp;
    00AC 2F04      MOV	R16,R20
    00AD 940E014A  CALL	pop_gset2
    00AF 9508      RET
FILE: F:\2007电子设计\古欣\twitest\twi_test\main_master.c
(0001) //ICC-AVR application builder : 2007-7-19 9:50:03
(0002) // Target : M16
(0003) // Crystal: 7.3728Mhz
(0004)  //主机从1到255发一个数，收一个数。从机接收到任何数都返回。
(0005)  //当主机收到的数为0x10时，从零开始发送。
(0006) #include "config.h"
(0007) 
(0008) void main(void)
(0009) {
(0010)  uint8 i=0,tmp=0;
_main:
  tmp                  --> R20
  i                    --> R22
    00B0 2766      CLR	R22
    00B1 2744      CLR	R20
(0011)  //re-enable interrupts
(0012)  DDRC=0X00;
    00B2 2422      CLR	R2
    00B3 BA24      OUT	0x14,R2
(0013)  PORTC=0x03; //使能内部上拉电阻
    00B4 E083      LDI	R24,3
    00B5 BB85      OUT	0x15,R24
(0014)  twi_master_init();
    00B6 940E004B  CALL	_twi_master_init
    00B8 C00E      RJMP	0x00C7
(0015)