i2c.h

此文档为采用FPGA实现的以太网MAC层

#include "sys.h"
#include "excalibur.h"

/* Change this define depending on what temperature sensor you have */
/* A0 indicates that last 3 I2C address bits are 000, and A5 is 101 */
#define A0

/* I2C Address - 1001 101x for A5 parts */
/* I2C Address - 1001 000x for A0 parts */
#ifdef A5
#define I2C_TEMP_ADDR 0x9A
#else
#define I2C_TEMP_ADDR 0x90
#endif

#define I2C_RTC_ADDR 0xD0

/* Write only register */
#define i2c_cmd_sta 0x80	/* Generated start/rstart condition */
#define i2c_cmd_sto 0x40	/* Generate stop condition */
#define i2c_cmd_rd 0x20		/* Read from slave */
#define i2c_cmd_wr 0x10		/* Write to slave */
#define i2c_cmd_ack 0x8		/* Ack=0 sends ACK, ACK=1 sends NACK */
#define i2c_cmd_iack 0x1	/* Clears interrupt when set to 1 */

/* Read only register */
#define i2c_status_rxack 0x80	/* 1 indicates NACK received, 0 is ACK */
#define i2c_status_busy 0x40	/* 1 after START, 0 after STOP */
#define i2c_status_al 0x20		/* 1 when arbitration has been lost */
#define i2c_status_tip 0x2		/* 1 when transferring data */
#define i2c_status_if			/* Set when one byte of transfer has occurred */

#define i2c_mode_write 0
#define i2c_mode_read 1

typedef volatile struct
{
	volatile int u16prescale_l;
	volatile int u16prescale_h;
	volatile int u16control; /* Bit 7 is enable, bit 6 is IE */
	volatile int u16buf;
	volatile int u16cmdstat;
} T_i2c;