Texas Instruments MSP50C6xx - Manual (Page 255)

Individual Instruction Descriptions
4-169 Assembly Language Instructions
4.14.73 SHLSPLS Shift Left String With Subtract PL
Syntax
[label] name dest, src Clock, clk Word, w With RPT, clk Class
SHLSPLS An, {adrs} Table 4–46 Table 4–46 1b
SHLSPLS An[~], An[~] n
S
+3 1 n
R
+3 3
Execution PH, PL
⇐
src << SV
dest
⇐
dest – PL
PC
⇐
PC + 1
Flags Affected OF, SF, ZF, CF are set accordingly
src is {adrs}:
TAG bit is set accordingly
Opcode
Instructions 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
SHLSPLS An, {adrs} 0 1 1 1 0 1 1 An adrs
x dma16 (for direct) or offset16 (long relative) [see section 4.13]
SHLSPLS An[~], An[~] 1 1 1 0 0 1 1 An 1 1 1 0 0 0 A~ ~A
Description Shift accumulator string or data memory string pointed by {adrs} to left n
SV
bits
(as specified by the SV register). This result is zero-filled on the right and either
zero-filled or sign-extended on the left (based on the setting of the extended
sign mode (XM) bit in the status register). The upper 16 bits are latched into
the PH register. The lower 16 bits of the result PL are subtracted from the
destination accumulator (or its offset). This instruction propagates the shifted
bit to the next accumulator.
Syntax Description
SHLSPLS An, {adrs} Shift RAM string left, subtract PL from An
SHLSPLS An[~], An[~] Shift An[~] string left, subtract PL from An[~]
See Also SHLSPL , SHLTPL , SHLTPLS, SHLAPL, SHLAPLS
Example 4.14.73.1 SHLSPLS A0, *R4++R5
Shift the string pointed by the byte address stored in R4 by n
SV
bits to the left, subtract the shifted value
(PL) from the value in the accumulator string in A0, and store the result in accumulator string A0. Add
R5 to R4 and store result in R4. After execution of the instruction, PH is copied to the next to the last
accumulator of the string.
Example 4.14.73.2 SHLSPLS A2, *R1++
Shift the string pointed by the byte address stored in R1 by n
SV
bits to the left, subtract the shifted value
(PL) from the value in the accumulator string in A2, and store the result in accumulator string A2.
Increment R1 (by 2). After execution of the instruction, PH is copied to the next to the last accumulator
of the string.
Example 4.14.73.3 SHLSPLS A1, A1
Shift the accumulator string A1 by n
SV
bits to the left, subtract the lower 16-bits of shifted value (PL) from
A1, and store the result in A1. After execution PH contains the upper 16 bits of the 32-bit shift.