Multi-Master IIC Interface (MMIIC)
Data Sheet
MC68HC908SR12MC68HC08SR12 — Rev. 5.0
302
Multi-Master IIC Interface (MMIIC)
Freescale Semiconductor
MMTXAK — MMIIC Transmit Acknowledge Enable
This bit is set to disable the MMIIC from sending out an acknowledge
signal to the bus at the 9th clock bit after receiving 8 data bits. When
MMTXAK is cleared, an acknowledge signal will be sent at the 9th
clock bit. Reset clears this bit.
1 = MMIIC does not send acknowledge signals at 9th clock bit
0 = MMIIC sends acknowledge signal at 9th clock bit
REPSEN — Repeated Start Enable
This bit is set to enable repeated START signal to be generated when
in master mode transfer (MMAST = 1). The REPSEN bit is cleared by
hardware after the completion of repeated START signal or when the
MMAST bit is cleared. Reset clears this bit.
1 = Repeated START signal will be generated if MMAST bit is set
0 = No repeated START signal will be generated
MMCRCBYTE — MMIIC CRC Byte
In receive mode, this bit is set by software to indicate that the next
receiving byte will be the packet error checking (PEC) data.
In master receive mode, after completion of CRC generation on the
received PEC data, an acknowledge signal is sent if MMTXAK = 0; no
acknowledge is sent If MMTXAK = 1.
In slave receive mode, no acknowledge signal is sent if a CRC error
is detected on the received PEC data. If no CRC error is detected, an
acknowledge signal is sent if MMTXAK = 0; no acknowledge is sent If
MMTXAK = 1.
Under normal operation, the user software should clear MMTXAK bit
before setting MMCRCBYTE bit to ensure that an acknowledge signal
is sent when no CRC error is detected.
The MMCRCBYTE bit should not be set in transmit mode. This bit is
cleared by the next START signal. Reset also clears this bit.
1 = Next receiving byte is the packet error checking (PEC) data
0 = Next receiving byte is not PEC data