Document No.: FT_000060
FT4232H QUAD HIGH SPEED USB TO MULTIPURPOSE UART/MPSSE IC
Datasheet Version 2.09
Clearance No.: FTDI#78
WRSTB#
RDSTB#
Figure 4.7 Synchronous Bit-Bang Mode Timing Interface Example
It should be noted that the FT4232H does not output the WRSTB# or RDSTB# signals when configured in
bit-bang mode. Figure 4.7. and Table 4.2 show these signals for illustration purposes only.
NAME
t1
Description
Current pin state is read
RDSTB# is set inactive and data on the paralle I/O pins is read and sent to the USB host.
RDSTB# is set active again, and any pins that are output will change to their new data
1 clock cycle to allow for data setup
t2
t3
t4
WRSTB# goes active. This indicates that the host PC has written new data to the I/O parallel data
WRSTB# goes inactive
t5
t6
Table 4.2 Synchronous Bit-Bang Mode Timing Interface Example Timings
WRSTB# = this output indicates when new data has been written to the I/O pins from the Host PC (via
the USB interface).
RDSTB# = this output rising edge indicates when data has been read from the I/O pins and sent to the
Host PC (via the USB interface).
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