Freescale Semiconductor MPC8260 - Manual (Page 851)

Multi-Channel Controllers (MCCs)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 28-3
— Section 28.3.4, “Channel-Specific SS7 Parameters”
Note that the DPRAM memory corresponding to the inactive channels can be used for other
purposes.
• Channel extra parameters. Each channel use 8 bytes of extra parameters placed in the DPRAM at
offset XTRABASE + 8*CH_NUM (relative to the DPRAM base address). XTRABASE is one of
the global MCC parameters. Refer to
Section 28.4, “Channel Extra Parameters.” Note that the
DPRAM memory corresponding to the inactive channels can be used for other purposes.
• Superchannel table (used only if superchannelled timeslots are defined in SIRAM programming).
This table is placed in the DPRAM from the offset SCTPBASE (relative to the DPRAM base
address). SCTPBASE is one of the global MCC parameters. The super channel table is described
in
Section 28.5.1, “Superchannel Table.”
• BD tables placed in the external memory. All the BD tables associated with one MCC must reside
in a 512-KByte segment. The absolute base addresses of a channel BD table is MCCBASE +
8*RBASE (for the receiver) and MCCBASE + 8*TBASE (for the transmitter). MCCBASE is one
of the global MCC parameters and RBASE/TBASE are channel extra parameters. Each BD table
is a circular queue. One BD includes status bits, start address and length of a data buffer.
Figure 28-1 shows the BD structure for one MCC.
• Circular interrupt tables placed in the external memory. There is one table for the transmitter
interrupts (base address TINTBASE) and between one and four tables for receiver interrupts (base
address RINTBASE0–RINTBASE4). TINTBASE and RINTBASE0–RINTBASE4 are global
MCC parameters.
• Three registers (MCCE, MCCM, and MCCF) at described in Section 28.8.1, “MCC Event Register
(MCCE)/Mask Register (MCCM),” and Section 28.6, “MCC Configuration Registers (MCCFx).”
Figure 28-1. BD Structure for One MCC
Channel j TxBD
Table
Channel 0 Parameter
Channel 1 Parameter
Channel j Extra RBASE
TBASE
Global MCC MCCBASE
DPRAM
Buffer Descriptor
+
+
Channel j RxBD
Table
External Memory
512 Kbytes
x8
x8
DPRAM_base
Table Base Address
Parameter
Parameters