MPC823 datasheet(37/74 Pages) MOTOROLA

37 / 74 page

Communication Processor Module

MOTOROLA

MPC823 REFERENCE MANUAL

16-415

REN—SMCx Receive Enable

0 = SMCx receiver disabled.

1 = SMCx receiver enabled.

16.11.7.10 SMCx TRANSPARENT RECEIVE BUFFER DESCRIPTOR. Using receive

(RX) buffer descriptors, the communication processor module reports information about the

received data for each buffer and closes the current buffer, generates a maskable interrupt,

and starts to receive data into the next buffer after one of the following events occurs:

• An overrun error occurs

• A full receive buffer is detected

• The ENTER HUNT MODE command is issued

E—Empty

0 = The data buffer associated with this RX buffer descriptor is filled with received data

or data reception has been aborted due to an error condition. The core is free to

examine or write to any fields of this RX buffer descriptor. The communication

processor module does not use this buffer descriptor as long as the E bit is zero.

1 = The data buffer associated with this buffer descriptor is empty or is currently

receiving data. This RX buffer descriptor and its associated receive buffer are

owned by the communication processor module. Once the E bit is set, the core

must not write any fields of this RX buffer descriptor.

Bits 1, 4–5, 7–13, and 15—Reserved

These bits are reserved and must be set to 0.

Note:

The communication processor module sets all the status bits in this buffer

descriptor, but you must clear them before submitting the buffer descriptor to the

communication processor module.

OFFSET + 0

RES

RESERVED

RES

OFFSET + 2

DATA LENGTH

OFFSET + 4

RX DATA BUFFER POINTER

OFFSET + 6

NOTE: You are only responsible for initializing the items in bold.

MPC823 Datasheet(PDF) 37 Page - Motorola, Inc