Document No.: FT_000288
FT232H SINGLE CHANNEL HI-SPEED USB TO MULTIPURPOSE UART/FIFO IC
Datasheet Version 1.8
Clearance No.: FTDI #199
3.5.6 FT232H Pins used as a Fast Serial Interface
The FT232H can be configured for use with high-speed bi-directional isolated serial data. A proprietary
FTDI protocol designed to allow galvanic isolated devices to communicate synchronously with the FT232H
using just 4 signal wires (over two dual opto-isolators), and two power lines. The peripheral circuitry
controls the data transfer rate in both directions, whilst maintaining full data integrity. 12 Mbps (USB full
speed) data rates can be achieved when using the proper high speed opto-isolators (see App Note AN-
131).
When configured in this mode, the pins used and the descriptions of the signals are shown in Table 3.11.
Fast Serial Interface Configuration
Pin No.
Name
Type
Description
13
FSDI
INPUT
Fast serial data input.
Fast serial clock input.
14
15
FSCLK
FSDO
INPUT
Clock input to FT232H chip to clock data in or out.
OUTPUT
Fast serial data output.
Fast serial Clear To Send signal output.
16
FSCTS
OUTPUT
Driven low to indicate that the chip is ready to send
data
The Send Immediate / WakeUp signal combines two
functions on a single pin. If USB is in suspend mode
(PWREN# = 1) and remote wakeup is enabled in the
EEPROM , strobing this pin low will cause the device
to request a resume on the USB Bus. Normally, this
can be used to wake up the Host PC.
SIWU#
INPUT
28
During normal operation (PWREN# = 0), if this pin is
strobed low any data in the device RX buffer will be
sent out over USB on the next Bulk-IN request from
the drivers regardless of the pending packet size. This
can be used to optimize USB transfer speed for some
applications. Tie this pin to VCCIO if not used.
Table 3.11 Fast Serial Interface Configured Pin Descriptions
For a functional description of this mode, please refer to section 4.9
Copyright © 2012 Future Technology Devices International Limited
19
ETC [ ETC ]
