Document No.: FT_000648
FT121 ENHANCED USB DEVICE CONTROLLER WITH SPI SLAVE IC
Datasheet Version 1.2
Table of Contents
1
Typical Applications...................................................................... 2
1.1 Part Numbers...................................................................................... 2
1.2 USB Compliant.................................................................................... 2
Block Diagrams ............................................................................ 3
Device Pin Out and Signal Description.......................................... 6
3.1 TSSOP-16 Package Pin Out ................................................................. 6
3.2 QFN-16 Package Pin Out..................................................................... 6
3.3 Pin Description ................................................................................... 7
Function Description..................................................................... 9
4.1 Functional Block Descriptions............................................................. 9
4.2 Interrupt Modes................................................................................ 10
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4.3 SPI Slave Interface........................................................................... 10
4.3.1 4-wire write operation................................................................................................ 11
4.3.2 4-wire read operation................................................................................................. 11
4.3.3 3-wire write operation................................................................................................ 12
4.3.4 3-wire read operation................................................................................................. 12
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Endpoint Buffer Management ..................................................... 14
5.1 Endpoint Buffer Management in Default Mode .................................. 14
5.2 Endpoint Buffer Management in Enhanced Mode .............................. 15
Commands and Registers ........................................................... 17
6.1 Command Summary.......................................................................... 17
6.2 Initialization Commands................................................................... 22
6.2.1 Set Address Enable.................................................................................................... 22
6.2.2 Set Endpoint Enable................................................................................................... 22
6.2.3 Set Mode.................................................................................................................. 22
6.2.4 Set Interrupt............................................................................................................. 24
6.2.5 Set Endpoint Configuration (for Enhanced Mode) ........................................................... 24
6.3 Data Flow Commands ....................................................................... 25
6.3.1 Read Interrupt Register.............................................................................................. 25
6.3.2 Select Endpoint ......................................................................................................... 27
6.3.3 Read Last Transaction Status ...................................................................................... 27
6.3.4 Read Endpoint Status................................................................................................. 28
6.3.5 Read Buffer............................................................................................................... 29
6.3.6 Write Buffer .............................................................................................................. 29
6.3.7 Clear Buffer .............................................................................................................. 29
6.3.8 Validate Buffer .......................................................................................................... 29
6.3.9 Set Endpoint Status ................................................................................................... 30
6.3.10
Acknowledge Setup ................................................................................................ 30
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