Motorola MPC8260 - Manual (Page 726)

26-30 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part IV. Communications Processor Module
26.5 The SMC in GCI Mode
The SMC can control the C/I and monitor channels of the GCI frame. When using the SCIT
conÞguration of a GCI, one SMC can handle SCIT channel 0 and the other can handle SCIT
channel 1. The main features of the SMC in GCI mode are as follows:
¥ Each SMC channel supports the C/I and monitor channels of the GCI (IOM-2) in
ISDN applications
¥ Two SMCs support both sets of C/I and monitor channels in SCIT channels 0 and 1
¥ Full-duplex operation
¥ Local loopback and echo capability for testing
To use the SMC GCI channels properly, the TSA must be conÞgured to route the monitor
and C/I channels to the preferred SMC. Chapter 14, ÒSerial Interface with Time-Slot
Assigner,Ó describes how to program this conÞguration. GCI mode is selected by setting
SMCMR[SM] to 0b10. Section 26.2.1, ÒSMC Mode Registers (SMCMR1/SMCMR2)Ó
describes other protocol-speciÞc SMCMR bits.
26.5.1 SMC GCI Parameter RAM
The GCI parameter RAM differs from that for UART and transparent mode. The CP
accesses each SMCÕs GCI parameter table using a user-programmed pointer
(SMCx_BASE) located in the parameter RAM; see Section 13.5.2, ÒParameter RAM.Ó
Each SMC GCI parameter RAM table can be placed at any 64-byte aligned address in the
dual-port RAMÕs general-purpose area (banks #1Ð#8). In GCI mode, parameter RAM
contains the BDs instead of pointers to them. Compare Table 26-17 with Table 26-2 to see
the differences. (In GCI mode, the SMC has no extra protocol-speciÞc parameter RAM.)
Table 26-17. SMC GCI Parameter RAM Memory Map
Offset 1
1 From the pointer value programmed in SMCx_BASE: SMC1_BASE at 0x87FC, SMC2_BASE at 0x88FC.
Name Width Description
0x00 M_RxBD Half word Monitor channel RxBD. See Section 26.5.5, ÒSMC GCI Monitor Channel RxBD.Ó
0x02 M_TxBD Half word Monitor channel TxBD. See Section 26.5.6, ÒSMC GCI Monitor Channel TxBD.Ó
0x04 CI_RxBD Half word C/I channel RxBD. See Section 26.5.7, ÒSMC GCI C/I Channel RxBD.Ó
0x06 CI_TxBD Half word C/I channel TxBD. See Section 26.5.8, ÒSMC GCI C/I Channel TxBD.Ó
0x08 RSTATE 2
2 RSTATE, M_RxD, M_TxD, CI_RxD, and CI_TxD do not need to be accessed by the user in normal operation,
and are reserved for RISC use only.
Word Rx/Tx Internal State
0x0C M_RxD 2 Half word Monitor Rx Data
0x0E M_TxD 2 Half word Monitor Tx Data
0x10 CI_RxD 2 Half word C/I Rx Data
0x12 CI_TxD 2 Half word C/I Tx Data