Lucent Technologies DSP1611, Information Manual, Page: 122 / 443

Information Manual DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
April 1998 Instruction Set
Lucent Technologies Inc.
DRAFT COPY
4-5
4.3 Addressing Modes
(continued)
4.3.2 Compound Addressing
Compound addressing is a memory read/write operation using only one pointer register. The term Z specifies a
source and a destination for a compound RAM read followed by a write sequence. The mnemonics for Z are a
shorthand notation for the compound addressing functions explained below and shown in
Table 4-1 . The term
temp used in the descriptions is a hypothetical register used for illustration only. Note that postincrementation can
occur after either Step 2 or Step 3 in
Table 4-1 .
Note: M can be 0, 1, 2, or 3. R can be one of the general set of registers in Table 4-9 . R and rM must not be the
same register (e.g., r1pz : r1). The two alphanumerics in mnemonics zp, pz, m2, and jk stand for the postin-
crements after Step 2 and Step 3. z is zero, p is plus 1, m is minus 1, 2 is plus 2, and j and k are increments
from the j and k registers.
Table 4-1. Compound Addressing Instructions
Instruction Operations
Z : R Step 1 Step 2 Step 3
*rMzp : R TEMP = R R = *rM *rM++ = TEMP
*rMpz : R TEMP = R R = *rM++ *rM = TEMP
*rMm2 : R TEMP = R R = *rM– – *rM++2 = TEMP
*rMjk : R TEMP = R R = *rM++j *rM++k = TEMP