Computer Hardware User's Guide

Parallel FLOAT and STF FLOAT||STF
13-105 Assembly Language Instructions
Syntax FLOAT src2, dst1
|| STF src3 , dst2
Operation float (src2 ) → dst1
|| src3 → dst2
Operands src2 indirect ( disp = 0, 1, IR0, IR1)
dst1 register (R n 1, 0 ≤ n 1 ≤ 7)
src3 register (R n 2, 0 ≤ n 2 ≤ 7)
dst2 register ( disp = 0, 1, IR0, IR1)
This instruction’s operands have been augmented in the following devices:
’C31 silicon revision 6.0 or greater
’C32 silicon revision 2.0 or greater
src2 indirect ( disp = 0, 1, IR0, IR1) or any CPU register
dst1 register (R n 1, 0 ≤ n 1 ≤ 7)
src3 register (R n 2, 0 ≤ n 2 ≤ 7)
dst2 register ( disp = 0, 1, IR0, IR1)
Opcode
31 24 23 16 8 7 015
110101
dst 1 src 2 dst 21
src 3
000
Description An integer-to-floating-point conversion is performed. All registers are read at
the beginning and loaded at the end of the execute cycle. If one of the parallel
operations (STF) reads from a register and the operation being performed in
parallel (FLOAT) writes to the same register, then STF accepts the contents
of the register as input before it is modified by FLOAT.
If src2 and dst2 point to the same location, src2 is read before the write to dst2.
Cycles 1
Status Bits These condition flags are modified only if the destination register is R7–R0.
LUF Unaffected
LV Unaffected
UF 0
N 1 if a negative result is generated; 0 otherwise
Z 1 if a 0 result is generated; 0 otherwise
V 0
C Unaffected
OVM Operation is affected by OVM bit value.
Mode Bit