FT122Q-R FTDI, FT122Q-R Datasheet - Page 28

• Manufacturer Part Number: FT122Q-R
• Description: USB Interface IC USB CONTROLLER W/ PARALLEL BUS IC
• Manufacturer: FTDI

Specifications of FT122Q-R

• Rohs: yes
• Product: USB 2.0
• Interface Type: Parallel
• Operating Supply Voltage: 1.65 V to 3.6 V, 4 V to 5.5 V
• Operating Supply Current: 3.9 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-28
• Minimum Operating Temperature: - 40 C

Followed by Read Buffer command, the Clear Buffer command should be issued after all data has been
read out from the endpoint buffer. This is to free the buffer to receive next packet from USB host.
6.3.8 Validate Buffer
Command
Data
Followed by Write Buffer command, the Validate Buffer command should be issued after all data has been
written to the endpoint buffer. This is to set the buffer full flag so that the packet can be sent to USB host
when IN token arrives.
6.3.9 Set Endpoint Status
Command
Data
Table 6-18 Endpoint Control Register
6.3.10 Acknowledge Setup
Command
Data
When receiving a SETUP packet the FT122 will flush the IN buffer and disable the Validate Buffer and
Clear Buffer commands for both Control IN and Control OUT endpoints. The MCU shall read and process
the SETUP packet, and then issue the Acknowledge Setup command to re-enable the Validate Buffer and
Clear Buffer commands. The Acknowledge Setup command must be sent to both Control IN and Control
OUT endpoints.
6.4
7-1
Bit
0
General Commands
Stall
Reserved
: FAh
: None
: 40-45h (40-4Fh for Enhanced Mode)
: Write 1 byte
: F1h
: None
Symbol
Copyright © 2012 Future Technology Devices International Limited
0b’xxxxxxx
FT122 ENHANCED USB DEVICE CONTROLLER WITH PARALLEL
Reset
0
0: Disable the endpoint STALL state.
1: Enable the endpoint STALL state.
For EP0 OUT (control OUT endpoint) the STALL state will
automatically be cleared by receiving a SETUP packet.
When this bit is written to ‘0’, the endpoint will
reinitialize. Any data in the endpoint buffer will be
flushed away, and the PID for next packet will carry
DATA0 flag.
Reserved
BUS
Description
Document No.: FT_000647
Clearance No.: FTDI#
IC
Datasheet Version 1.0
313
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