Motorola MPC823e Reference Manual page 486

Communication Processor Module
I—Current Function Descriptor Number of Iterations
This bit is only used by the RISC microcontroller, so you do not need to modify it in any way.
TAP—Current Function Descriptor Number of Taps
The bit is only used by the RISC microcontroller, so you do not need to modify it in any way.
CBASE—Current Function Descriptor Cbase
The bit defines the current function descriptor base address of the coefficients. It is only
used by the RISC microcontroller, so you do not need to modify it in any way.
XPTR—Current Function Descriptor Pointer to Sample Pointer
The bit is only used by the RISC microcontroller, so you do not need to modify it in any way.
YPTR—Current Function Descriptor Pointer to Output Buffer Pointer
The bit is only used by the RISC microcontroller, so you do not need to modify it in any way.
M—Current Function Descriptor Sample Buffer Size-1
The bit is only used by the RISC microcontroller, so you do not need to modify it in any way.
N—Current Function Descriptor Output Buffer Size-1
The bit is only used by the RISC microcontroller, so you do not need to modify it in any way.
K—Current Function Descriptor Coefficient Buffer Size-1
The bit is only used by the RISC microcontroller, so you do not need to modify it in any way.
16.3.3.2.3 DSP Commands. The following commands are issued to the CPM command
register (CPCR) and their functionality is described in Table 16-6.
• INIT DSP CHAIN—Deactivates the corresponding chain. The function descriptor
pointer is initialized to the starting address provided in the function descriptor table.
• START DSP CHAIN—Activates the corresponding chain.
16-32 MPC823e REFERENCE MANUAL MOTOROLA