Maxim-integrated MAXQ622 Manual de usuario descargar pdf (Pagina 168)

MAXQ612/MAXQ622 User’s Guide

Maxim Integrated 11-13

11.4.7 I

C Slave Address Register (I2CSLA)

Bit 7: Reserved. Reads returns zero.

Bits 6 to 0: I

C Slave Address Register (I2CSLA[6:0]). These address bits contain the address of the I

C device.

When a match to this address is detected, the I

C controller automatically acknowledges the transmitter with the

I2CACK bit value if the I

C module is enabled (I2CEN = 1). The I2CAMI flag is set to 1 and the I2CMST bit is cleared

to 0. An interrupt is generated to the CPU if enabled.

11.5 I

C Examples

11.5.1 I

C Example: Master Mode, Transmit

C configured as master, transmit to slave address 08h:

; Setup for Master Mode Transmit

move I2CCN, #003h ; I2CEN = 1, I2CMST = 1

call wait_busy ; Polling routine to wait for I2CBUSY to clear

move I2CCN, #043h ; I2CEN = 1, I2CMST = 1, I2CMODE = 0, I2CSTART = 1

call wait_start ; Polling routine to wait for I2CSTART to clear

call wait_busy ; Polling routine to wait for I2CBUSY to clear

move I2CIE.1, #01h ; Enable Transmit Complete Interrupt

move I2CBUF, #008h ; Slave address set to 08h

call wait_tx_complete ; Wait for transmit interrupt

;; Verify ACK from slave

move ACC, I2CST ; Move I2C Status Register to accumulator

and #080h ; Check for NACK bit set in status register

cmp #000h

jump ne, FAIL ; If NACK bit set, handle retransmission, else continue

move I2CBUF, #0aah ; Byte to transmit

call wait_tx_complete ; Wait for transmit interrupt

;; Verify ACK

I2CSLA

C Slave Address Register

M4[0Ah]

Bit # 7 6 5 4 3 2 1 0

Name — I2CSLA6 I2CSLA5 I2CSLA4 I2CSLA3 I2CSLA2 I2CSLA1 I2CSLA0

Reset 0 0 0 0 0 0 0 0

Access r rw rw rw rw rw rw rw

1 2 ... 163 164 165 166 167 168 169 170 171 172 173 ... 254 255

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Maxim-integrated MAXQ622 Manual de usuario Pagina 168