Copyright © 2014 Future Technology Devices International Limited

4

Document No.: FT_000647

FT122 ENHANCED USB DEVICE CONTROLLER WITH PARALLEL

BUS

Clearance No.: FTDI#

313

Table of Contents

1

Typical Applications...................................................................... 2

1.1

Part Numbers...................................................................................... 2

1.2

USB Compliant .................................................................................... 2

2

Block Diagrams ............................................................................ 3

3

Device Pin Out and Signal Description.......................................... 6

3.1

TSSOP-28 Package Pin Out ................................................................. 6

3.2

QFN-28 Package Pin Out..................................................................... 6

3.3

Pin Description ................................................................................... 7

4

Function Description..................................................................... 9

4.1

Functional Block Descriptions ............................................................. 9

4.2

Interrupt Modes................................................................................ 10

5

Endpoint Buffer Management ..................................................... 11

5.1

Endpoint Buffer Management in Default Mode .................................. 11

5.2

Endpoint Buffer Management in Enhanced Mode .............................. 12

6

Commands and Registers ........................................................... 14

6.1

Command Summary.......................................................................... 14

6.2

Initialization Commands ................................................................... 19

6.2.1

Set Address Enable .................................................................................................... 19

6.2.2

Set Endpoint Enable ................................................................................................... 19

6.2.3

Set Mode .................................................................................................................. 19

6.2.4

Set DMA ................................................................................................................... 21

6.2.5

Set Endpoint Configuration (for Enhanced Mode) ........................................................... 22

6.3

Data Flow Commands ....................................................................... 23

6.3.1

Read Interrupt Register .............................................................................................. 23

6.3.2

Select Endpoint ......................................................................................................... 25

6.3.3

Read Last Transaction Status ...................................................................................... 25

6.3.4

Read Endpoint Status ................................................................................................. 26

6.3.5

Read Buffer............................................................................................................... 27

6.3.6

Write Buffer .............................................................................................................. 27

6.3.7

Clear Buffer .............................................................................................................. 27

6.3.8

Validate Buffer .......................................................................................................... 28

6.3.9

Set Endpoint Status ................................................................................................... 28

6.3.10

Acknowledge Setup ................................................................................................ 28

6.4

General Commands........................................................................... 28

6.4.1

Read Current Frame Number....................................................................................... 29

6.4.2

Send Resume ............................................................................................................ 29

6.4.3

Set Buffer Interrupt Mode ........................................................................................... 29

6.4.4

Read Vendor ID ......................................................................................................... 30