z8f1601 ZiLOG Semiconductor, z8f1601 Datasheet - Page 201

• Manufacturer Part Number: z8f1601
• Description: Z8 Encore!? Microcontroller With Flash Memory And 10-bit A/d Converter
• Manufacturer: ZiLOG Semiconductor

Assembly Language Syntax
eZ8 CPU Instruction Notation
PS017609-0803
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 opcode-dependent. The fol-
lowing instruction examples illustrate the format of some basic assembly instructions and
the resulting object code produced by the assembler. This binary format must be followed
by users that prefer manual program coding or intend to implement their own assembler.
Example 1: If the contents of Registers 43H and 08H are added and the result is stored in
43H, the assembly syntax and resulting object code is:
Table 113. Assembly Language Syntax Example 1
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, a Working Register R0 - R15. If the contents of Register 43H and Working
Register R8 are added and the result is stored in 43H, the assembly syntax and resulting
object code is:
Table 114. Assembly Language Syntax Example 2
See the device-specific Product Specification to determine the exact register file range
available. The register file size varies, depending on the device type.
In the eZ8 CPU Instruction Summary and Description sections, the operands, condition
codes, status flags, and address modes are represented by a notational shorthand that is
described in Table 115
Assembly Language Code ADD
Object Code
Assembly Language Code ADD
Object Code
; value
; Register at address
04
04
01H
, is the source. The value
43H,
08
43H,
E8
Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
234H
08H
43
R8
43
.
(ADD dst, src)
(OPC src, dst)
(ADD dst, src)
(OPC src, dst)
01H
is written into the
eZ8 CPU Instruction Set
Z8 Encore!
®
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