Communication Processor Module
MOTOROLA MPC823e REFERENCE MANUAL 16-371
USB
COMMUNICATION
16
PROCESSOR MODULE
STAL—STALL Handshake Received (Host)
This bit indicates that the endpoint has responded with a STALL handshake. The endpoint
needs attention through the control pipe. This bit is written by the USB controller after it has
finished transmitting the associated data buffer.
TO—Time-Out
This bit indicates that the endpoint has failed to acknowledge this packet. This bit is written
by the USB controller after it has finished transmitting the associated data buffer.
UN—Underrun
This bit indicates that the USB controller has encountered a transmitter underrun condition
while transmitting the associated data buffer. This bit is written by the USB controller after it
has finished transmitting the associated data buffer.
DATA LENGTH
This field represents the number of octets that the communication processor module must
transmit from this buffer descriptor’s data buffer. It is never modified by the communication
processor module. This value must normally be greater than zero.
TX DATA BUFFER POINTER
This field always points to the first location of the associated data buffer and can be even or
odd. The buffer can reside in either internal or external memory.
16.10.8.4 USB SLAVE ADDRESS REGISTER. The 8-bit, memory-mapped, read/write
USB address register (USADR) holds the address for this USB port in slave mode.
Bit 0—Reserved
This bit is reserved and must be set to 0.
SAD—Slave Address 0–6
This field contains the slave address for the USB port.
USADR
BIT 0 1 2 3 4 5 6 7
FIELD RESERVED SAD
RESET 00
R/W R/W R/W
ADDR (IMMR & 0xFFFF0000) + 0xA01
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