Texas Instruments TMS320C67X/C67X+ DSP Car Speaker User Manual


 
Control Register File
CPU Data Paths and Control2-10 SPRU733
2.7.3 Addressing Mode Register (AMR)
For each of the eight registers (A4–A7, B4–B7) that can perform linear or circu-
lar addressing, the addressing mode register (AMR) specifies the addressing
mode. A 2-bit field for each register selects the address modification mode:
linear (the default) or circular mode. With circular addressing, the field also
specifies which BK (block size) field to use for a circular buffer. In addition, the
buffer must be aligned on a byte boundary equal to the block size. The mode
select fields and block size fields are shown in Figure 23 and described in
Table 25.
Figure 23. Addressing Mode Register (AMR)
31 26 25 21 20 16
Reserved
BK1 BK0
R-0 R/W-0 R/W-0
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
B7 MODE
B6 MODE B5 MODE B4 MODE A7 MODE A6 MODE A5 MODE A4 MODE
R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0
Legend: R = Readable by the MVC instruction; W = Writeable by the MVC instruction; -n = value after reset
Table 25. Addressing Mode Register (AMR) Field Descriptions
Bit Field Value Description
3126 Reserved 0 Reserved. The reserved bit location is always read as 0. A value written to
this field has no effect.
2521 BK1 01Fh Block size field 1. A 5-bit value used in calculating block sizes for circular
addressing. Table 26 shows block size calculations for all 32 possibilities.
Block size (in bytes) = 2
(N+1)
, where N is the 5-bit value in BK1
2016 BK0 01Fh Block size field 0. A 5-bit value used in calculating block sizes for circular
addressing. Table 26 shows block size calculations for all 32 possibilities.
Block size (in bytes) = 2
(N+1)
, where N is the 5-bit value in BK0
1514 B7 MODE 03h Address mode selection for register file B7.
0 Linear modification (default at reset)
1h Circular addressing using the BK0 field
2h Circular addressing using the BK1 field
3h Reserved