36
1745D–ATARM–04-Nov-05
AT91M55800A
11.9 Memory Access Waveforms
Figure 11-15 through Figure 11-18 show examples of the two alternative protocols for external
memory read access.
Figure 11-15. Standard Read Protocol with no t
DF
Read Mem 1
Write Mem 1
Read Mem 1
Read Mem 2
Write Mem 2
Read Mem 2
Chip Select
Change Wait
A0 - A23
NRD
NWE
NCS1
NCS2
D0 - D15 (Mem 1)
D0 - D15 (Mem 2)
D0 - D15 (AT91)
MCK
t
WHDX
t
WHDX