Program Bank Register

The Program Bank Register (PBR or K) exists on the 65c816. It tells the processor which bank to fetch the next opcode from. It is 8 bits wide. It is cleared to zero on reset.^[2] PHK pushes it onto the stack, but there is no PLK to pull it.

PBR is affected only by:

• RTI
• RTL
• JML
• JSL
• JMP absolute long

There is also a program bank register on the GSU.^[1] It can be used to specify any mapped bank address.^[3]

See Also

• RTI
• Program Counter
• Data Bank Register
• LJMP

Reference

1. paragraph 4.5 on page 2-4-5 of Book II
2. section 2.9 on page 7 of 65c816 datasheet, https://westerndesigncenter.com/wdc/documentation/w65c816s.pdf
3. Figure 2-3-2 Super FX Memory Map on page 2-3-4 of Book II