Document No.: FT_000061
FT2232H DUAL HIGH SPEED USB TO MULTIPURPOSE UART/FIFO IC
Datasheet Version 2.09
Clearance No.: FTDI#77
4.5 FT245 Asynchronous FIFO Interface Mode Description
The FT2232H can be configured as a dual channel asynchronous FIFO interface. This mode is similar to
the synchronous FIFO interface with the exception that the data is written to or read from the FIFO on
the falling edge of the WR# or RD# signals.
This mode does not provide a CLKOUT signal and it does not expect an OE# input signal. The following
diagrams illustrate the asynchronous FIFO mode timing.
T5
T6
RXF#
T2
T1
RD#
T4
T3
Valid Data
D[7...0]
Figure 4.5 FT245 asynchronous FIFO Interface READ Signal Waveforms
T11
T12
TXE#
T8
T7
WR#
D[7...0]
T9
T10
Valid Data
Figure 4.6 FT245 asynchronous FIFO Interface WRITE Signal Waveforms
Time
T1
Description
Min
50
Max
Units
RD# input pulse width
RD# to RD pre-charge
ns
ns
ns
ns
ns
ns
ns
ns
T2
T5 +T6
20
T3
RD# input active to data output valid
Valid data hold time after RD# input rising edge
RD# inactive to RXF# output inactive
RXF# output inactive after RD# cycle
WR# active pulse width
50
T4
0
T5
0
25
67
T6
33
T7
10
T8
WR# to WR# pre-charge time
50
Copyright © 2010 Future Technology Devices International Limited
26
FTDI [ FUTURE TECHNOLOGY DEVICES INTERNATIONAL LTD. ]
