Z8 Encore!® Motor Control Flash MCUs
Product Specification
278
; Working Register R7, is the source. The contents
of R7 is
; written into R4.
LD 234H, #%01 ; Another Load (LD) instruction with two operands.
; The first operand, Extended Mode Register Address
234H,
; identifies the destination. The second operand,
Immediate Data
; value 01h, is the source. The value 01h is
written into the
; Register at address 234h.
Assembly Language Syntax
For proper instruction execution, eZ8 CPU assembly language syntax requires that the
operands be written as ‘destination, source’. After assembly, the object code usually has
the operands in the order ’source, destination’, but ordering is Op Code-dependent. The
following instruction examples illustrate the format of some basic assembly instructions
and the resulting object code produced by the assembler. This binary format must be fol-
lowed by users that prefer manual program coding or intend to implement their own
assembler.
Example 1. If the contents of registers 43hand 08hare added and the result is stored in
43h, the assembly syntax and resulting object code is:
Assembly Language Code
Object Code
ADD 43H,
04 08
08h (ADD dst, src)
43 (OPC src, dst)
Example 2. In general, when an instruction format requires an 8-bit register address, that
address can specify any register location in the range 0–255 or, using Escaped Mode
Addressing in working registers R0–R15. If the contents of Register 43hand Working
Register R8 are added and the result is stored in 43h, the assembly syntax and resulting
object code is:
Assembly Language Code
Object Code
ADD 43H,
04 E8
R8 (ADD dst, src)
43 (OPC src, dst)
PS024604-1005
P R E L I M I N A R Y
eZ8 CPU Instruction Set
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