M E M O R Y Device Speed - Xycom XVME-100 Manual

XVME-100 Manual
March, 1987
These t h r e e jumpers a r c independent o f each o t h e r. W h e n b o t h t h e d a t a space
select and t h e program space select jumpers arc out, the bank w i l l be disabled f r o m
VMEbus accesses.

2.4.3 M e m o r y Device Speed

Two j u m p e r s e x i s t f o r each b a n k ( 4 t o t a l ) t o d e f i n e t h e speed o f t h e memory
devices. S e l e c t i o n s a r e 1 0 0 , 150, 200, a n d 2 5 0 n s devices. T a b l e 2 - 4 l i s t s t h e
jumpers and speed d e f i n i t i o n f o r each device.
•
VMEbus access t i m i n g i s a f u n c t i o n o f the memory device speed o f the bank being
accessed. D a t a strobe asserted t o D TA C K * asserted w i l l t y p i c a l l y b e 100 n s p l u s
the chosen access t i m e . D a t a strobe negated t o D T A C K * negated w i l l b e 5 0 u s
typical.
•
Table 2-4. M e m o r y Device Speed Jumpers
BANK 1
Speed Select
100ns
150ns
200ns
250ns
BANK 2
Speed Select
100ns
150ns
200ns
250ns
* = Factory shipped configuration
2-11
Jumpers
J6 J 7
Out Out
Out In
In
Out
In* In*
Jumpers
J4 J 5
Out Out
Out In
In
Out
In* In*