Copyright © 2015 Future Technology Devices International Limited

28

FT234XD USB TO BASIC UART IC

Version 1.2

Document No.: FT_000753 Clearance No.: FTDI#324

8 Internal MTP Memory Configuration

The FT234XD includes an internal MTP memory which holds the USB configuration descriptors, other

configuration data for the chip and also user data areas. Following a power-on reset or a USB reset the

FT234XD will scan its internal MTP memory and read the USB configuration descriptors stored there.

In many cases, the default values programmed into the MTP memory will be suitable and no re-

programming will be necessary. The defaults can be found in Section 8.1.

The MTP memory in the FT234XD can be programmed over USB if the values need to be changed for a

particular application. Further details of this are provided from section 8.2 onwards.

Users who do not have their own USB Vendor ID but who would like to use a unique Product ID in their

design can apply to FTDI for a free block of unique PIDs. See TN_100 – USB Vendor ID/Product ID

Guidelines for more details.

8.1 Default Values

The default factory programmed values of the internal MTP memory are shown in Table 8.1.

Parameter

Value

Notes

USB Vendor ID (VID)

0403h

FTDI default VID (hex)

USB Product UD (PID)

6015h

FTDI default PID (hex)

Serial Number Enabled?

Yes

Serial Number

See Note

A unique serial number is generated and

programmed into the MTP memory during device

final test.

Pull down I/O Pins in USB

Suspend

Disabled

Enabling this option will make the device pull down

on the UART interface lines when in USB suspend

mode (PWREN# is high).

Manufacturer Name

FTDI

Product Description

FT234XD BASIC

UART

Max Bus Power Current

90mA

Power Source

Bus Powered

Device Type

FT234XD

USB Version

0200

Returns USB 2.0 device description to the host.

Note: The device is a USB 2.0 Full Speed device

(12Mb/s) as opposed to a USB 2.0 High Speed

device (480Mb/s).

Remote Wake Up

Disabled

Taking RI# low will wake up the USB host controller

from suspend in approximately 20 ms.

DBUS Drive Current

Strength

4mA

Options are 4mA, 8mA, 12mA, 16mA

DBUS slew rate

Slow

Options are slow or fast

DBUS Schmitt Trigger

Normal

Options are normal or Schmitt