Motorola MPC823e - Page 518

Communication Processor Module
16-64 MPC823e REFERENCE MANUAL MOTOROLA
DSP
COMMUNICATION
16
PROCESSOR MODULE
The first half-word is composed of the following bits:
S—STOP
0 = Do not stop after executing this function descriptor.
1 = Stop after executing this function descriptor.
Bits 1, 4–10—Reserved
These bits are reserved and must be set to 0.
W—Wrap (Final Function Descriptor in Table)
0 = This is not the last function descriptor in the function descriptor table.
1 = This is the last function descriptor in the function descriptor table. After this buffer
has been used, the CPM processes the first function descriptor that the FDBASE
index pointer points to in the table. The number of function descriptors in this table
are programmable and determined only by the W bit and overall space constraints
of the memory.
I—Interrupt
0 = No interrupt is generated after this function is processed.
1 = A maskable interrupt is generated after this function is processed.
OPCODE—Function Operation Code
This field specifies the function to be executed. Table 16-6 contains the value for this field.
16.3.4.8.3 DEMOD Parameter Packet. The DEMOD parameter packet is composed of
seven 16-bit half-words and is described in the table below.
Table 16-15. DEMOD Parameter Packet
ADDRESS NAME DESCRIPTION
Half-word 1 I Number of Iterations
Half-word 2 K Modulation Table Size-1. The minimum modulation table size is 8 (2 sin/cos pairs).
Half-word 3 DPTR Pointer to Modulation Table Pointer and AGC constant
Half-word 4 M Samples Buffer Size-1. The minimum sample buffer size is 8 (2 samples).
Half-word 5 XYPTR Pointer to a structure composed of the input sample data pointer and the output
buffer pointer
Half-word 6 N Output Buffer Size-1. The minimum output buffer size is 8 (2 outputs).
Half-word 7 RES Reserved