COBHAM GR712RC - 5.3 Memory mapped IO

GR712RC-UM, Jun 2017, Version 2.9 56 www.cobham.com/gaisler
GR712RC
5.3 Memory mapped IO
Accesses to IO have similar timing as PROM accesses. The IO select (IOSN) and output enable
(OEN) signals are delayed one clock to provide stable address before IOSN is asserted. All accesses
are performed as non-consecutive accesses as shown in figure 21. The data2 phase is extended when
waitstates are added.
Figure 21. I/O read cycle (0-waitstates)
data1
address
iosn
data
oen
lead-out
sdclk
A1
D1
lead-in data2
Figure 22. I/O write cycle (0-waitstates)
address
iosn
data
writen
lead-out
sdclk
A1
D1
lead-in
data