Motorola MPC823e Reference Manual page 692

Communication Processor Module
• TMP—A temporary register that is only used by the communication processor module.
• TMP_MB—A temporary register that is only used by the communication processor
module.
Note: For 8-bit addresses, the eight high-order bits in HMASK must be masked out
(cleared). The eight low-order bits of HMASK and HADDRx must contain the
address byte that immediately follows the opening flag. For, example, to
recognize a frame that begins 0x7E, 0x68, 0xAA, using 16-bit address
recognition, HADDRx must contain 0xAA68 and HMASK must contain 0xFFFF.
Refer to Figure 16-79 for details.
16-BIT ADDRESS RECOGNITION
FLAG ADDRESS
0x7E 0x68
HMASK
HADDR1
HADDR2
HADDR3
HADDR4
RECOGNIZES ONE 16-BIT ADDRESS (HADDR1) AND
THE 16-BIT BROADCAST ADDRESS (HADDR2)
Figure 16-79. HDLC Address Recognition Example
16.9.16.5 PROGRAMMING THE SCCS IN HDLC MODE.The core configures the serial
communication controllers to operate in one of the protocols set in the MODE field of the
GSMR_L. The SCCx HDLC controller uses the same data structure as other modes and it
supports multibuffer operation and address comparisons. The reception errors are reported
through the RX buffer descriptor and the transmit errors are reported through the TX buffer
descriptor.
16-238
ADDRESS CONTROL
ETC.
0xAA 0x44
0xFFFF
0xAA68
0xFFFF
0xAA68
0xAA68
MPC823e REFERENCE MANUAL
8-BIT ADDRESS RECOGNITION
FLAG ADDRESS CONTROL
0x7E 0x55 0x44
HMASK 0x00FF
0xXX55
HADDR1
0xXX55
HADDR2
0xXX55
HADDR3
0xXX55
HADDR4
RECOGNIZES A SINGLE 8-BIT ADDRESS (HADDR1)
ETC.
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