Copyright © 2014 Future Technology Devices International Limited

22

Document No.: FT_000646

FT120 USB DEVICE CONTROLLER WITH PARALLEL BUS IC

Datasheet Version 1.2

Clearance No.: FTDI#

291

6.3.7 Clear Buffer

Command

: F2h

Data

: None

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

: FAh

Data

: None

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

: 40-45h (4ih where ‘i’ is the endpoint index (EPI) as defined in Table 5-1 and

Table 5-2)

Data

: Write 1 byte

Bit

Symbol

Reset

Description

0

Stall

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 cleared, the endpoint will reinitialize. Any

data in the endpoint buffer will be flushed away, and the

PID for next packet will carry DATA0 flag.

7-1

Reserved

0b’xxxxxxx Reserved

Table 6-13 Endpoint Control Register

6.3.10 Acknowledge Setup

Command

: F1h

Data

: None

When receiving a SETUP packet the FT120 will flush the IN buffer and disable the Validate Buffer and

Clear Buffer commands for both IN and 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 IN and OUT endpoints.