Iic Control Register (Iicxc1) - ROHS MC9S08QE128 Reference Manual

Inter-Integrated Circuit (S08IICV2)
12.3.3

IIC Control Register (IICxC1)

7
R
IICEN
W
Reset 0
= Unimplemented or Reserved
Field
7 IIC Enable — The IICEN bit determines whether the IIC module is enabled.
IICEN 0 IIC is not enabled.
1 IIC is enabled.
6 IIC Interrupt Enable — The IICIE bit determines whether an IIC interrupt is requested.
IICIE 0 IIC interrupt request not enabled.
1 IIC interrupt request enabled.
5 Master Mode Select — The MST bit is changed from a 0 to a 1 when a START signal is generated on the bus
MST and master mode is selected. When this bit changes from a 1 to a 0 a STOP signal is generated and the mode
of operation changes from master to slave.
0 Slave mode.
1 Master mode.
4 Transmit Mode Select — The TX bit selects the direction of master and slave transfers. In master mode this bit
TX should be set according to the type of transfer required. Therefore, for address cycles, this bit will always be high.
When addressed as a slave this bit should be set by software according to the SRW bit in the status register.
0 Receive.
1 Transmit.
3 Transmit Acknowledge Enable — This bit specifies the value driven onto the SDA during data acknowledge
TXAK cycles for both master and slave receivers.
0 An acknowledge signal will be sent out to the bus after receiving one data byte.
1 No acknowledge signal response is sent.
2 Repeat START — Writing a 1 to this bit will generate a repeated START condition provided it is the current
RSTA master. This bit will always be read as a low. Attempting a repeat at the wrong time will result in loss of arbitration.
224
6 5
IICIE MST
0 0
Figure 12-5. IIC Control Register (IICxC1)
Table 12-5. IICxC1 Field Descriptions
MC9S08QE128 MCU Series Reference Manual, Rev. 2
4 3
TX TXAK
0 0
Description
2 1
0 0
RSTA
0 0
Freescale Semiconductor
0
0
0