FT245BQ USB FIFO ( USB - Parallel ) I.C.
Figure 12
Microprocessor Interface Example
FT245BM
Microcontroller
25
FT245BQ
D0
D1
D2
D3
D4
D5
D6
D7
IO10
IO11
IO12
IO13
IO14
IO15
IO16
IO17
24
23
22
21
20
19
18
16
15
14
12
RD#
WR
IO20
IO21
IO22
IO23
TXE#
RXF#
11
SI / WU
IO24
( Optional )
Figure 12 illustrates a typical interface between the FT245BQ and a MicroController (MCU). This examples uses two
IO Ports of the MCU, one port (8 bits) to transfer data and the other port (4 / 5 bits) to monitor the TXE# and RXF#
status bits and generate the RD# and WR strobes to the FT245BQ as required. Optionally, SI / WU can be connected
to another IO pin if this function is required. If the SI / WU function is not required, tie this pin of the FT245BQ to
VCCIO. If the MCU is handling power management functions, then PWREN# should also be connected to an IO pin of
the MCU.
The 8 data bits of Port 1 can be shared with other peripherals when the MCU is not accessing the FT245BQ.
DS245BQ Version 1.7
© Future Technology Devices Intl. Ltd. 2005
Page 22 of 24
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