P R O G R A M M
A B L E O P T I O N S E L E C T
The remaining POS registers are used for address and
i n t e r r u p t s e l e c t i o n s . T h e s e r e g i s t e r s a r e p r o g r a m m e d b y
t h e u s e r t h r o u g h t h e I B M i n s t a l l a t i o n u t i l i t y s u p p l i e d
with the PS/2. These registers are read/write but should
n o t b e w r i t t e n t o b y u s e r s o f t w a r e . T h e b i t d e f i n i t i o n s
of these registers are given in figures 16(a) and 16(b).
+-------+
D7 | CHEN1 |----- Channel enable
+-------+
D6 | INS11 |--+
+-------+ +-- Interrupt select
D5 | INS10 |--+
+-------+
D4 | ADS13 |--+
(a) +-------+ |
D3 | ADS12 | |
+-------+ +-- Address select
D2 | ADS11 | |
+-------+ |
D1 | ADS10 |--+
+-------+
D0 | CEN |--- Card enable
+-------+
+-------+
D7 | CHEN2 |----- Channel enable
+-------+
D6 | INS21 |--+
+-------+ +-- Interrupt select
D5 | INS20 |--+
+-------+
D4 | ADS23 |--+
(b) +-------+ |
D3 | ADS22 | |
+-------+ +-- Address select
D2 | ADS21 | |
+-------+ |
D1 | ADS20 |--+
+-------+
D0 | 0 |----- Reserved
+-------+
Figure 16. DS-2000 POS implementation.
(a) POS location 102H
(b) POS location 103H
iii
