FT2232HQ-REEL FTDI, FT2232HQ-REEL Datasheet - Page 30

• Manufacturer Part Number: FT2232HQ-REEL
• Description: USB Interface IC USB HS to Dual UART/ FIFO/SPI/JTAG/I2C
• Manufacturer: FTDI

Specifications of FT2232HQ-REEL

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

4.6.1 MPSSE Adaptive Clocking
Adaptive clocking is a new MPSSE feature added to the FT2232H MPSSE engine.
The mode is effectively handshaking the CLK signal with a return clock RTCK. This is a technique used by
ARM processors.
The FT2232H will assert the CLK line and wait for the RTCK to be returned from the target device to
GPIOL3 line before changing the TDO (data out line).
Figure 4.8 Adaptive Clocking Interconnect
Figure 4.9: Adaptive Clocking waveform.
Adaptive clocking is not enabled by default.
See: AN_108 Command Processor for MPSSE and MCU Host Bus Emulation Modes.
RTCK
TDO
TCK
FT2232H
GPIOL3
TDO
TCK
Copyright © 2010 Future Technology Devices International Limited
FT2232H DUAL HIGH SPEED USB TO MULTIPURPOSE UART/FIFO IC
RTCK
ARM CPU
TDO changes on falling
edge of TCK
Document No.: FT_000061
Clearance No.: FTDI#77
Datasheet Version 2.10
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