Rainbow-electronics MAX7311 Bedienungsanleitung PDF herunterladen (Seite 8)

MAX7311

MAX7311 generates the acknowledge bit since the

MAX7311 is the recipient. When the MAX7311 is trans-

mitting to the master, the master generates the

acknowledge bit.

Slave Address

The MAX7311 has a 7-bit-long slave address (Figure 6).

The 8th bit following the 7-bit slave address is the R/W

bit. Set this bit low for a write command and high for a

read command.

Slave address pins AD2, AD1, and AD0 choose 1 of 64

slave ID addresses (Table 7).

Data Bus Transaction

The command byte is the first byte to follow the 8-bit

device slave address during a write transmission

(Table 1, Figure 7). The command byte is used to deter-

mine which of the following registers are written or read.

Writing to Port Registers

Transmit data to the MAX7311 by sending the device

slave address and setting the LSB to a logic zero. The

command byte is sent after the address and deter-

mines which registers receive the data following the

command byte (Figure 7).

2-Wire-Interfaced 16-Bit I/O Port Expander

with Interrupt

8 _______________________________________________________________________________________

SDA

A6 A5 A4 A3 A2 A1 A0

MSB LSB

ACKR/W

PROGRAMMABLE

Figure 6. Slave Address

COMMAND BYTE

ADDRESS (HEX)

FUNCTION PROTOCOL

POWER-UP

DEFAULT

0x00 Input port 1 Read byte XXXX XXXX

0x01 Input port 2 Read byte XXXX XXXX

0x02 Output port 1 Read/write byte 1111 1111

0x03 Output port 2 Read/write byte 1111 1111

0x04 Port 1 polarity inversion Read/write byte 0000 0000

0x05 Port 2 polarity inversion Read/write byte 0000 0000

0x06 Port 1 configuration Read/write byte 1111 1111

0x07 Port 2 configuration Read/write byte 1111 1111

0x08 Timeout register Read/write byte 0000 0001

0xFF Factory reserved. (Do not write to this register.) ——

Table 1. Command Byte Register

123456789

SCL

SDA

S A0000001 76543210A76543210A0A

SLAVE ADDRESS

COMMAND BYTE PORT 1 DATA PORT 2 DATA

R/W

ACKNOWLEDGE

FROM SLAVE

ACKNOWLEDGE

FROM SLAVE

START

CONDITION

ACKNOWLEDGE

FROM SLAVE

ACKNOWLEDGE

FROM SLAVE

WRITE TO PORT

DATA OUT PORT 1

READ FROM PORT 2

Figure 7. Writes to Output Registers Through Write Byte Protocol

1 2 3 4 5 6 7 8 9 10 11 12 13 ... 16 17

Kommentare zu diesen Handbüchern

Keine Kommentare

Rainbow-electronics MAX7311 Bedienungsanleitung Seite 8

Kommentare zu diesen Handbüchern

Verwandte Produkte und Handbücher für Schalttafel Rainbow-electronics MAX7311