Decoding The Register File; Figure 19-3 Register File Access - ARM ARM1176JZF-S Technical Reference Manual

19.3

Decoding the register file

ARM DDI 0301H
ID012310
Each register file access uses the five bits of the register number in the instruction word. For
single-precision and integer accesses, the most significant four bits are in the Fm, Fn, or Fd field,
and the least significant bit is the M, N, or D bit for each instruction format. For instructions
with double-precision operands or destinations, the M, N, and D bit corresponding to a
double-precision access must be zero. Figure 19-3 shows the register file. See the ARM
Architecture Reference Manual for instruction formats and the positions of these bits.
31
S1
S3
S5
S7
S9
S11
S13
S15
S17
S19
S21
S23
S25
S27
S29
S31
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63
D0
0
D1
D2
D3
D4
D5
D6
D7
D8
D9
D10
D11
D12
D13
D14
D15
The VFP Register File
0
31
S0
S2
S4
S6
S8
S10
S12
S14
S16
S18
S20
S22
S24
S26
S28
S30

Figure 19-3 Register file access

0
19-5