ISD91200 Series Technical Reference Manual
Release Date: Sep 16, 2019
- 165 -
Revision 2.4
5.6.6
Register Description
I2C CONTROL REGISTER (I2C_CTL)
Register
Offset
R/W
Description
Reset Value
I2C_CTL
0x00
R/W
I2C Control Register
0x0000_0000
7
6
5
4
3
2
1
0
INTEN
I2CEN
STA
STO
SI
AA
Reserved
Bits
Description
[31:8]
Reserved
Reserved.
[7]
INTEN
Enable Interrupt
0 = Disable interrupt.
1 = Enable interrupt CPU.
[6]
I2CEN
I2C Controller Enable Bit
0 = Disable.
1 = Enable.
Set to enable I2C serial function block.
[5]
STA
I2C START Control Bit
Setting STA to logic 1 will enter master mode, the I2C hardware sends a START or
repeat START condition to bus when the bus is free.
[4]
STO
I2C STOP Control Bit
In master mode, set STO to transmit a STOP condition to bus. I2C hardware will
check the bus condition, when a STOP condition is detected this bit will be cleared
by hardware automatically. In slave mode, setting STO resets I2C hardware to the
defined “not addressed” slave mode. This means it is NO LONGER in the slave
receiver mode able receive data from the master transmit device.
[3]
SI
I2C Interrupt Flag
When a new SIO state is present in the I2C_STATUS register, the SI flag is set by
hardware, and if bit INTEN
(I2C_CTL[7]) is set, the I2C interrupt is requested. SI
must be cleared by software. Clear SI is by writing one to this bit.
[2]
AA
Assert Acknowledge Control Bit
When AA=1 prior to address or data received, an acknowledge (ACK - low level to
SDA) will be returned during the acknowledge clock pulse on the SCL line when:.
1. A slave is acknowledging the address sent from master,
2. The receiver devices are acknowledging the data sent by transmitter.
When AA = 0 prior to address or data received, a Not acknowledged (high level to
SDA) will be returned during the acknowledge clock pulse on the SCL line.
[1:0]
Reserved
Reserved.