FT121Q-R FTDI, FT121Q-R Datasheet - Page 30

• Manufacturer Part Number: FT121Q-R
• Description: USB Interface IC USB CONTROLLER W/SPI SLAVE IC
• Manufacturer: FTDI

Specifications of FT121Q-R

• Rohs: yes
• Product: USB 2.0
• Interface Type: SPI, USB
• Operating Supply Voltage: 4 V to 5.5 V
• Operating Supply Current: 3.9 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-16
• Minimum Operating Temperature: - 40 C

6.4
6.4.1 Read Current Frame Number
Command
Data
Table 6-18 Frame Number LSB Register
Table 6-19 Frame Number MSB Register
6.4.2 Send Resume
Command
Data
To perform remote-wakeup when suspended, the MCU needs to issue Send Resume command. The
FT121 will send an upstream resume signal for a period of 10 ms. If the clock is not running during
suspend, the MCU needs to wakeup FT121 by driving the SUSPEND pin to LOW, followed by the Send
Resume command.
6.4.3 Set 3-wire Mode
Command
Data
This command is used to enable the 3-wire SPI mode. Once enabled, the MOSI pin will become bi-
directional line and the MISO pin is not functional. Both SPI master and slave will drive data on the MOSI
line.
7-0
2-0
7-3
Bit
Bit
General Commands
Frame Number LSB
Frame Number MSB
Reserved
: F5h
: Read One or Two Bytes
: F6h
: None
: E8h
: None
Symbol
Symbol
Copyright © 2012 Future Technology Devices International Limited
FT121 ENHANCED USB DEVICE CONTROLLER WITH SPI SLAVE IC
0b’00000
0b’000
Reset
Reset
00h
Frame number for last received SOF, byte 1 (least
significant byte)
Frame number for last received SOF, byte 2 (Most
significant byte)
Reserved
Description
Description
Document No.: FT_000648
Clearance No.: FTDI#
Datasheet Version 1.0
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