FT2232HL-REEL FTDI, FT2232HL-REEL Datasheet - Page 43

• Manufacturer Part Number: FT2232HL-REEL
• Description: USB Interface IC USB HS to Dual UART/ FIFO/SPI/JTAG/I2C
• Manufacturer: FTDI

Specifications of FT2232HL-REEL

• Mounting Style: SMD/SMT
• Package / Case: LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.12 Send Immediate / Wake Up (SIWU#)
The SIWU# function is available in the FIFO modes and in bitbang mode.
The Send Immediate portion is used to flush data from the chip back to the PC. This can be used to get
short packets of data back to the PC without waiting for the latency timer to expire.
This mechanism should only be used when you have stopped sending data to the chip to avoid overrun.
The data transfer is flagged to the USB host by the falling edge of the signal.
Figure 4.23: Using SIWU#
When the pin is being used for a Wake Up function to wake up a sleeping PC a 20ms negative pulse on
this pin is required.
Notes
1.
2.
3. If a Pull-down is enabled, the FT2232H will not wake up from suspend.
CLKOUT
SIWU#
WR#
D7-D0
When using remote wake-up, ensure the resistors are pulled-up in suspend. Also ensure peripheral
designs do not allow any current sink paths that may partially power the peripheral.
wake-up is disabled, the peripheral must draw no more than 500uA in suspend.
If remote wake-up is enabled, a peripheral is allowed to draw up to 2.5mA in suspend. If remote
Copyright © 2010 Future Technology Devices International Limited
FT2232H DUAL HIGH SPEED USB TO MULTIPURPOSE UART/FIFO IC
Document No.: FT_000061
Clearance No.: FTDI#77
Datasheet Version 2.10
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