Philips 8-bit microcontroller with two-clock 80C51 core UM10109 用户手册

 

© Koninklijke Philips Electronics N.V. 2005. All rights reserved.

After a repeated START condition, I

2

C-bus may switch to the Master Transmitter Mode.

In the Slave Receiver Mode, data bytes are received from a master transmitter. To 
initialize the Slave Receiver Mode, the user should write the slave address to the Slave 
Address Register (I2ADR) and the I

2

C Control Register (I2CON) should be configured as 

follows:

CRSEL is not used for slave mode. I2EN must be set = 1 to enable I

2

C function. AA bit 

must be set = 1 to acknowledge its own slave address or the general call address. STA, 
STO and SI are cleared to 0.

After I2ADR and I2CON are initialized, the interface waits until it is addressed by its own 
address or general address followed by the data direction bit which is 0(W). If the direction 
bit is 1(R), it will enter Slave Transmitter Mode. After the address and the direction bit have 
been received, the SI bit is set and a valid status code can be read from the Status 
Register(I2STAT). Refer to 

 for the status codes and actions.

S

R

A

slave address

logic 0 = write

logic 1 = read

from master to slave

from slave to master

A = acknowledge (SDA LOW)
A = not acknowledge (SDA HIGH)
S = START condition

002aaa930

DATA

DATA

data transferred

(n Bytes 

+ acknowledge)

A

A

P

S

R

A

SLA

logic 0 = write

logic 1 = read

from master to slave

from slave to master

002aaa931

DATA

DATA

data transferred

(n Bytes 

+ acknowledge)

A

W

A

SLA

DATA

A

P

A

RS

A = acknowledge (SDA LOW)
A = not acknowledge (SDA HIGH)
S = START condition
P = STOP condition
SLA = slave address
RS = repeat START condition

-

I2EN

STA

STO

SI

AA

-

CRSEL

value

-

1

0

0

0

1

-

-