HE84760B Datasheet, PDF (43/51 Pages) King blillion Electronics Co.,Ltd. – 8-bit Micro-controller

KING BILLION ELECTRONICS CO., LTD
駿億電子股份有限公司
HE84760B
HE80004 Series
22. Extension Register Access
The extension registers can be accessed through the extension port control registers EXTAS and
EXTDA. User can read/write the extension register easily and the control timing is generated by
hardware automatically. The following code shows how to access the extension registers.
Read Extension Register:
LDA #0x00h ; load #0x00h data to A Register
STA EXTAS ; store A register data to the extension port address register.
LDA EXTDA ; store the extension register (0x00h) data to A Register.
Write Extension Register:
LDA #0x03h ; load #0x03h data to A Register
STA EXTAS ; store A register data to the extension port address register.
LDA #0x18h ; load #0x18h data to A Register
STA EXTDA ; store A register data to the extension port data register.
June 29, 2005
43
V1.0
This specification is subject to change without notice. Please contact sales person for the latest version before use.