
Communication Processor Module
MOTOROLA
MPC823 USER’S MANUAL
16-33
DSP
COMMUNICATION
16
PROCESSOR
MODULE
FDBASE—Function Descriptor Table Base Address
This index pointer defines the location in system memory where the function descriptor
starts. However, you must initialize it.
FD_PTR—Function Descriptor Pointer
This pointer points to the current function descriptor address. It is only used by the RISC
microcontroller, so you do not need to modify it in any way.
DSTATE—Current State
This bit defines the internal state of the RISC microcontroller. It is only used by the RISC
microcontroller, so you do not need to modify it in any way.
DSTATUS—Current Function Descriptor Status
This bit defines the current status of the current function descriptor. It is only used by the
RISC microcontroller, so you do not need to modify it in any way.
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.
Table 16-7. DSP Parameter RAM Memory Map
ADDRESS
NAME
WIDTH
DESCRIPTION
DSP Base + 0x00
FDBASE
Word
Function Descriptor Table Base Address
DSP Base + 0x04
FD_PTR
Word
Function Descriptor Pointer
DSP Base + 0x08
DSTATE
Word
DSP State
DSP Base + 0x10
DSTATUS
Half-word
Current Function Descriptor Status
DSP Base + 0x12
I
Half-word
Current Function Descriptor Number of Iterations
DSP Base + 0x14
TAP
Half-word
Current Function Descriptor Number of TAPs
DSP Base + 0x16
CBASE
Half-word
Current Function Descriptor Cbase Pointer
DSP Base + 0x18
—
Half-word
Current Function Descriptor Sample Buffer Size-1
DSP Base + 0x1A
XPTR
Half-word
Current Function Descriptor Pointer to Sample Pointer
DSP Base + 0x1C
—
Half-word
Current Function Descriptor Output Buffer Size-1
DSP Base + 0x1E
YPTR
Half-word
Current Function Descriptor Pointer to Output Buffer Pointer
DSP Base + 0x20
M
Half-word
Current Function Descriptor Sample Buffer Size-1
DSP Base + 0x22
—
Half-word
Current Function Descriptor Sample Buffer Pointer
DSP Base + 0x24
N
Half-word
Current Function Descriptor Output Buffer Size-1
DSP Base + 0x26
—
Half-word
Current Function Descriptor Output Buffer Pointer
DSP Base + 0x28
K
Half-word
Current Function Descriptor Coefficient Buffer Size-1
DSP Base + 2A
—
Half-word
Current Function Descriptor Coefficient Buffer Pointer
NOTE:
You are only responsible for initializing the items in bold.
DSP1 Base = (IMMR & 0xFFFF0000) + 0x3EC0 and DSP2 base = (IMMR & 0xFFFF0000) + 0x3FC0.