Stores a byte of data from a general-purpose register into a specified location in memory and possibly places the address in another general-purpose register.
| Bits | Value |
|---|---|
| 0-5 | 31 |
| 6-10 | RS |
| 11-15 | RA |
| 16-20 | RB |
| 21-30 | 247 |
| 31 | / |
| stbux | RS, RA, RB |
The stbux instruction stores bits 24-31 of the source general-purpose register (GPR) RS into the byte in storage addressed by the effective address (EA).
If GPR RA is not 0, the EA is the sum of the contents of GPR RA and the contents of GPR RB. If RA is 0, then the EA is the contents of GPR RB.
If GPR RA does not equal 0 and the storage access does not cause an Alignment Interrupt, then the EA is stored in GPR RA.
The stbux instruction exists only in one syntax form and does not affect the Fixed-Point Exception Register or Condition Register Field 0.
The following code stores the contents of GPR 6 into a location in memory and places the address in GPR 4:
.csect data[rw] buffer: .long 0 # Assume GPR 6 contains 0x0000 0060. # Assume GPR 4 conteains 0x0000 0000. # Assume GPR 19 contains the address of buffer. .csect text[pr] stbux 6,4,19 # Buffer now contains 0x60. # GPR 4 contains the address of buffer.
Fixed-Point Load and Store with Update Instructions .