
TMS320C240, TMS320F240
DSP CONTROLLERS
SPRS042D – OCTOBER 1996 – REVISED NOVEMBER 1998
53
POST OFFICE BOX 1443
HOUSTON, TEXAS 77251–1443
instruction set summary (continued)
Table 13. TMS320x240 Opcode Symbols
SYMBOL
DESCRIPTION
A
Address
ACC
Accumulator
ACCB
Accumulator buffer
ARx
Auxiliary register value (0–7)
BITx
4-bit field that specifies which bit to test for the BIT instruction
BMAR
Block-move address register
DBMR
Dynamic bit-manipulation register
I
Addressing-mode bit
II...II
Immediate operand value
INTM
Interrupt-mode flag bit
INTR#
Interrupt vector number
K
Constant
PREG
Product register
PROG
Program memory
RPTC
Repeat counter
SHF, SHFT
3/4-bit shift value
TC
Test-control bit
T P
Two bits used by the conditional execution instructions to represent the conditions TC, NTC, and BIO.
T P
Meaning
0 0
0 1
1 0
1 1
BIO low
TC=1
TC=0
None of the above conditions
TREGn
Temporary register n (n = 0, 1, or 2)
Z L V C
4-bit field representing the following conditions:
Z:
ACC = 0
L:
ACC < 0
V:
Overflow
C:
Carry
A conditional instruction contains two of these 4-bit fields. The 4-LSB field of the instruction is a 4-bit mask field. A 1 in the
corresponding mask bit indicates that the condition is being tested. The second 4-bit field (bits 4–7) indicates the state of
the conditions designated by the mask bits as being tested. For example, to test for ACC
≥
0, the Z and L fields are set while
the V and C fields are not set. The next 4-bit field contains the state of the conditions to test. The Z field is set to indicate
testing of the condition ACC = 0, and the L field is reset to indicate testing of the condition ACC
≥
0. The conditions possible
with these 8 bits are shown in the BCND and CC instructions. To determine if the conditions are met, the 4-LSB bit mask
is ANDed with the conditions. If any bits are set, the conditions are met.