Motorola MPC860 PowerQUICC, User Manual

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36-6 MPC860 PowerQUICC UserÕs Manual MOTOROLA
Part V. The Communications Processor Module
36.8 DSP CP Commands
Once the DSP parameters are in place, use
INIT DSP
and
START DSP
to begin processing of
the FD chain; see Table 36-4 for command descriptions.
36.9 DSP Function Priority within the CPM
The execution of DSP functions has a priority level within the CPM that tracks the priority
level programmed for IDMA; see Section 19.3, ÒCommunicating with the Peripherals.Ó
The IDMA priority (and thus the DSP priority) is programmed in the RCCR; see
1
Offset from DSP base. DSP1 base is 0x1EC0; DSP2 base is 0x1FC0.
Table 36-3. DSPx Parameter RAM Memory Map
Offset
1
Name Width Description
0x00 FDBASE Word Function descriptor chain base address.
0x04 FD_PTR Word Current FD pointer
0x08 DSTATE Word DSP state
0x0C Ñ Word Reserved
0x10 DSTATUS Hword Current FD status
0x12 I Hword Current FD number_of_iterations
0x14 TAP Hword Current FD number_of_taps
0x16 CBASE Hword Current FD coefÞcient buffer base
0x18 Ñ Hword Current FD sample buffer_size - 1
0x1A XPTR Hword Current FD pointer to input buffer
0x1C Ñ Hword Current FD output buffer_size - 1
0x1E YPTR Hword Current FD pointer to output buffer
0x20 M Hword Current FD input buffer_size - 1
0x22 Ñ Hword Current FD input buffer data pointer
0x24 N Hword Current FD output buffer_size - 1
0x26 Ñ Hword Current FD output buffer data pointer
0x28 K Hword Current FD coefÞcient buffer_size - 1
0x2A Ñ Hword Current FD coefÞcient buffer data pointer
Table 36-4. DSP Opcodes
Command Description
INIT DSP
Initialize DSP chain. Deactivates the current chain and initializes the current FD pointer (FD_PTR) to
the FD chain base address (FDBASE).
START DSP
Start DSP chain. Activates the current chain.