45111 Datasheet, PDF (122/184 Pages) List of Unclassifed Manufacturers – 14-DAY MONEY BACK GUARANTEE

13 Appendix C: SX Instruction Set
The Affects column indicates the flags and registers the given instruction may affect. Depending on the
kind of instruction, flags and/or registers are always affected, or only on certain results of the
instruction. Table 27 - Flags and Registers, below, describes these flags and registers.
Table 27 - Flags and Registers
Symbol
C
DC
FSR
fr
M
op.bit
OPT
PC
PD
!port
TO
W
Z
Definition
The carry flag
The digit-carry flag
The file select register
The file register
The mode register
The specified bit of the specified operand
The options register
The program counter
The power-down flag
The specified I/O port data direction register
The time-out flag
The working register
The zero flag
The Coding column indicates how the given command will assemble, including binary values and
mnemonic instructions. Some commands assemble into multiple, simpler commands. Table 28 - Binary
Symbols, below, describes the binary symbols.
Table 28 - Binary Symbols
Symbol
b
f
k
Definition
Bit address
File register address
Constant
Any instruction that performs a skip will only skip one instruction word. To avoid strange results, care must be
taken to make sure that a single word instruction immediately follows the skipping instruction.
An exception to this rule are skip instructions that are immediately followed by a BANK or PAGE
instruction. Here (provided that the tested condition is true), two instructions will be skipped, i.e. the
BANK or PAGE instruction plus the next one. This is useful for conditional branching to another page
where a PAGE instruction precedes a JMP. If several PAGE and BANK instructions immediately follow
a skip instruction then they are all skipped plus the next instruction and a clock cycle is consumed for
each.
Many instructions are adversely affected by the carry flag when CARRYX (Add/Sub with C) is specified. Be
careful to follow the special notes within the instruction descriptions concerning this.
Page 122 • SX-Key/Blitz Development System Manual 2.0 • Parallax, Inc.