UM012811-0904
Addressing
Modes
eZ8 CPU
User Manual
21
Figure 8. Register Addressing Using 12-Bit Addresses
Register Addressing Using 8-Bit Addresses
Registers or Register Pairs may be accessed using 8-bit addresses supplied in the oper-
ands. Any of the 256 registers on the current Register File Page can be accessed using 8-
bit addressing. The upper 4-bits of the 12-bit address is provided by the Page Pointer,
RP[3:0]. The full 12-bit address is given by {RP[3:0], Address[7:0]}.
Figure 9 illustrates using 8-bit addressing, the destination and/or source address specified
corresponds to the a register in the Register File.
Two 12-bit
Program Memory
Addresses
(dst, src)
Three Operand
Instruction
(Example)
Opcode
src[11:4]
{src[3:0},
dst[11:8]}
dst[7:0]
Source
Destination
Register File
Register
Register
12-bit address is
dst[11:0]
12-bit address is
src[11:0]
