AT91M40800-33AI Datasheet, PDF (31/153 Pages) ATMEL Corporation – ARM® Thumb® Microcontrollers

External Wait
1354D–ATARM–08/02
AT91X40 Series
Figure 19. Data Float Output Time
MCK
ADDR
NCS
NRD
(1)
(2)
tDF
D0 - D15
Notes: 1. Early Read Protocol
2. Standard Read Protocol
The NWAIT input can be used to add wait states at any time. NWAIT is active low and is
detected on the rising edge of the clock.
If NWAIT is low at the rising edge of the clock, the EBI adds a wait state and changes
neither the output signals nor its internal counters and state. When NWAIT is de-
asserted, the EBI finishes the access sequence.
The NWAIT signal must meet setup and hold requirements on the rising edge of the
clock.
Figure 20. External Wait
MCK
ADDR
NWAIT
NCS
NWE
NRD
(1)
(2)
Notes: 1. Early Read Protocol
2. Standard Read Protocol
31