Buffer Blue Preliminary Specification; 1 . 0 General; Pin List - Tandy 1000 SL Technical Reference Manual

BUFFER BLUE PRELIMINARY SPECIFICATION
1 . 0 GENERAL
1.1
F u n c t i o n a l
D e s c r i p t i o n
The B u f f e r B l u e Custom I C
i s
a VLSI ASIC f o r u s e i n a PC/XT
t y p e a r c h i t e c t u r e u s i n g a n 8086 m i c r o p r o c e s s o r . I t c o m p r i s e s t h e
f o l l o w i n g
elements:
-
8237 E q u i v q l e n t .
-
DRAM c o n t r o l .
-
A d d r e s s b u f f e r i n g and d e c o d i n g .
-
D a t a C o n v e r s i o n a n d B u f f e r i n g .
I t is
c o n t a i n e d i n a
1 0 0
p i n f l a t p a c k a g e s u i t a b l e f o r s u r f a c e
mount
i ng
.
2.0 PIN LIST
PIN
NAME QW.
vcc
GND
4
4
ADO
-
AD15 16
ADR16
-
ADR19 4
so
-
s2 3
BH EB 1
RQ/GTB
1
READY
1
RESET 1
I/o
B i d i r .
B i d i r .
I n p u t s
I n p u t
B i d i r .
o u t p u t
o u t p u t
DESCRIPTION
Power i n p u t s
G r o u n d s
M u l t i p l e x e d a d d r e s s a n d
d a t a s i g n a l s f o r
c o n n e c t i o n t o 8086 CPU,
ROM
d a t a , a n d 16 b i t RAM
d a t a .
A d d r e s s i n p u t s f r o m CPU,
A d d r e s s o u t p u t s f r o m DMA.
S t a t u s i n p u t s f r o m CPU.
Bus High E n a b l e f r o m CPU
o r DMA.
Bus c o n t r o l h a n d s h a k i n g
w i t h CPU.
CPU r e a d y s i g n a l ,
a c t i v e
h i g h . T h i s s i g n a l
i s
s y n c h r o n i z e d w i t h C l o c k .
CPU
Reset
s i g n a l , a c t i v e
h i g h . T h i s s i g n a l
i s
s y n c h r o n i z e d w i t h C l o c k .
1