Motorola MPC823e Reference Manual page 876

Communication Processor Module
16.11.7.12 SMCx TRANSPARENT EVENT REGISTER. When a serial management
controller is in transparent mode, the 8-bit memory-mapped SMCx event register is referred
to as the SMCx transparent event (SMCE–Transparent) register. It is used to generate
interrupts and report events recognized by the SMCx channel. When an event is recognized,
the serial management controller sets the corresponding bit in this register. Interrupts
generated by this register can be masked in the SMCM–Transparent register.
A bit is cleared by writing a 1 (writing a zero has no effect) and more than one bit can be
cleared at a time. All unmasked bits must be cleared before the communication processor
module clears the internal interrupt request. This register is cleared at reset and can be read
at any time.
SMCE–TRANSPARENT
BIT 0 1
FIELD RESERVED
RESET 0
R/W R/W
ADDR
Bits 0–2 and 4—Reserved
These bits are reserved and must be set to 0.
TXE—TX Error
This bit indicates that an underrun error has occurred on the transmitter channel.
BSY—Busy Condition
This bit indicates that a character has been received and discarded due to a lack of buffers.
Reception begins after a new buffer is provided. You can execute an ENTER HUNT MODE
command to make the receiver wait for resynchronization.
TX—TX Buffer
This bit indicates that a buffer has been transmitted. If the L bit of the TX buffer descriptor is
set, this bit is set when the last data character starts being transmitted and you must wait
one character time to be sure that the data is completely sent over the transmit pin. If the L
bit of the TX buffer descriptor is cleared, this bit is set when the last data character is written
to the transmit FIFO and you must wait two character times to be sure that the data is
completely sent over the transmit pin.
RX—RX Buffer
This bit indicates that a data buffer has been received on the SMCx channel and its
associated RX buffer descriptor is now closed. This bit is set after the last character is written
to the buffer.
16-422
2 3 4
TXE RES
0 0
R/W R/W
(IMMR & 0xFFFF0000) + 0xA86 (SMC1), 0xA96 (SMC2)
MPC823e REFERENCE MANUAL
5 6 7
BSY TX RX
0 0 0
R/W R/W R/W
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