Zilog Z8F0130 - Manual (Page 49)

eZ8
™
CPU Core
User Manual
UM012820-0810 Addressing Modes
27
Addressing Modes
The eZ8
™
CPU provides six addressing modes:
•
Register (R)
•
Indirect Register (IR)
•
Indexed (X)
•
Direct (DA)
•
Relative (RA)
•
Immediate Data (IM)
With the exception of immediate data and condition codes, all operands
are expressed as either Register File, Program Memory, or Data Memory
addresses. Registers use 12-bit addresses in the range of
000h – FFFh .
Program Memory and Data Memory use 16-bit addresses (register pairs)
in the range of
0000h – FFFFh .
Register pairs can designate 16-bit values or memory addresses. Working
Register Pairs use 4-bit addresses and must be specified as an even-
numbered address in the range of 0, 2, ..., 14. Register Pairs use 8-bit
addresses and must be specified as an even-numbered address in the range
of 0, 2, …, 254.
In the following definitions of Addressing Modes, the use of 'register' can
imply a register, a register Pair, a working register, or a working register
pair, depending on the context.
Refer to the Zilog Product Specification specific to your Z8 Encore!
device for details on the Program, Data, and Register File memory types
and address ranges available.