FT4232HQ-REEL FTDI, FT4232HQ-REEL Datasheet - Page 21

• Manufacturer Part Number: FT4232HQ-REEL
• Description: USB Interface IC USB HS to Quad UART/ SPI/JTAG/I2C LQFN-64
• Manufacturer: FTDI
• Type: USB to High Speed UART/JTAG/SPI/I2Cr

Specifications of FT4232HQ-REEL

• Operating Supply Voltage: 1.8 V, 3.3 V
• Package / Case: QFN-64
• Description/function: USB High Speed to Dual UART/FIFO IC LQFP-64
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Operating Temperature Range: - 40 C to + 85 C
• Supply Current: 70 mA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.4.1 MPSSE Adaptive Clocking
Adaptive clocking is a new MPSSE feature added to the FT24232H MPSSE engine.
The mode is effectively handshaking the CLK signal with a return clock RTCK. This is a technique used by
ARM processors.
The FT4232H 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 4.5 Adaptive Clocking Interconnect
Figure 4.6: 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
FT4232H
GPIOL3
TDO
TCK
Copyright © 2010 Future Technology Devices International Limited
FT4232H QUAD HIGH SPEED USB TO MULTIPURPOSE UART/MPSSE IC
RTCK
ARM CPU
TDO changes on falling
edge of TCK
Document No.: FT_000060
Clearance No.: FTDI#78
Datasheet Version 2.10
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