MOTOROLA
Chapter 23. SCC Transparent Mode
23-9
Part IV. Communications Processor Module
23.9 Transparent Mode and the PSMR
The protocol-speciÞc mode register (PSMR) is not used by the transparent controller
because all transparent mode selections are made in the GSMR. If only half of an SCC
(transmitter or receiver) is running the transparent protocol, the other half (receiver or
transmitter) can support another protocol. In such a case, use the PSMR for the non-
transparent protocol.
23.10 SCC Transparent Receive Buffer Descriptor
(RxBD)
The CPM reports information about the received data for each buffer using an RxBD,
closes the current buffer, generates a maskable interrupt, and starts receiving data into the
next buffer after one of the following occurs:
¥
An error is detected.
¥
A full receive buffer is detected.
¥
An
ENTER
HUNT
MODE
command is Issued.
¥
A
CLOSE
RXBD
command is issued.
Table 23-7 describes RxBD status and control Þelds.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
E
Ñ
W
I
L
F
CM
Ñ
DE
Ñ
NO
Ñ
CR
OV
CD
2
Data Length
4
Rx Buffer Pointer
6
Figure 23-2. SCC Transparent Receive Buffer Descriptor (RxBD)
Table 23-7. SCC Transparent RxBD Status and Control Field
Descriptions
Bits
Name
Description
0
E
Empty.
0 The buffer is full or stopped receiving data because an error occurred. The core can read or write to
any Þelds of this RxBD. The CPM does not use this BD when RxBD[E] is zero.
1 The buffer is not full. This RxBD and buffer are owned by the CPM. Once E is set, the core should
not write any Þelds of this RxBD.
1
Ñ
Reserved, should be cleared.
2
W
Wrap (Þnal BD in table).
0 Not the last BD in the table.
1 Last BD in the table. After this buffer is used, the CPM receives data into the Þrst BD that RBASE
points to. The number of BDs in this table is determined only by RxBD[W] and overall space
constraints of the dual-port RAM.
Summary of Contents for MPC8260 PowerQUICC II
Page 1: ...MPC8260UM D 4 1999 Rev 0 MPC8260 PowerQUICC II UserÕs Manual ª ª ...
Page 66: ...lxvi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA ...
Page 88: ...1 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 120: ...2 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 138: ...Part II iv MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II Configuration and Reset ...
Page 184: ...4 46 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II ConÞguration and Reset ...
Page 202: ...Part III vi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 266: ...8 34 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 382: ...10 106 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 392: ...11 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 430: ...Part IV viii MOTOROLA Part IV Communications Processor Module ...
Page 490: ...14 36 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 524: ...17 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
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Page 980: ...A 4 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Appendixes ...
Page 1002: ...Index 22 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA INDEX ...
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