HMS38112 Datasheet, PDF (60/73 Pages) List of Unclassifed Manufacturers – 4-BIT SINGLE CHIP MICROCOMPUTERS

Chapter 5. Application
Guideline for S/W
1. All rams need to be initialized to zero in reset address for proper design.
2. Make the output ports `H` after reset.
3. Do not use WDTR instruction in subroutine.
4. Before reading the input port the waiting time should be more than 200uS.
5. To decrease current consumption, make the output port as high in normal routine except
for key scan strobe and STOP mode.
6. We recommend you do not use all 64 bytes in a page. You had better write ` BR $` in
unused area. This will help you prevent unusual operation of MCU.
7. Be careful not to use long call or branch (CALL,BL) with arithmetic manipulation.
If you want to use branch right after arithmetic manipulation, the long call or branch will be
against your intention.
 ^{ex) LAR}
; The value of R ports -> Accumulator
ALEI 14 ; Aõ14 : S = 1, A 14 : S = 0
BL TRUE ; S is always 1 because BL is composed of LPBI and BR.
-------------- Fail
 ^LAR
; The value of R ports -> Accumulator
ALEI 14 ; Aõ14 : S = 1, A 14 : S = 0
BR TRUE ; When S is 1 Branch will occur. Otherwise Branch will not occur and
LAK
; next instruction will be operated.
-------------- Right
5-1