link to page 11 link to page 11 link to page 11 link to page 11 link to page 11 link to page 29 FT232R USB UART IC DatasheetVersion 2.16 Document No.: FT_000053 Clearance No.: FTDI# 38 Pin No.NameTypeDescription this pin to power external logic if required. This pin can also be used to supply the VCCIO pin. 20 VCC PWR +3.3V to +5.25V supply to the device core. (see Note 1) 25 AGND PWR Device analogue ground supply for internal clock multiplier Table 3.2 Power and Ground GroupPin No.NameTypeDescription 8, 24 NC NC No internal connection 19 RESET# Input Active low reset pin. This can be used by an external device to reset the FT232R. If not required can be left unconnected, or pulled up to VCC. Puts the device into IC test mode. Must be tied to GND for normal 26 TEST Input operation, otherwise the device will appear to fail. Input 12MHz Oscillator Cell. Optional – Can be left unconnected for 27 OSCI Input normal operation. (see Note 2) 28 OSCO Output Output from 12MHZ Oscillator Cell. Optional – Can be left unconnected for normal operation if internal Oscillator is used. (see Note 2) Table 3.3 Miscellaneous Signal GroupPin No.NameTypeDescription 1 TXD Output Transmit Asynchronous Data Output. 2 DTR# Output Data Terminal Ready Control Output / Handshake Signal. 3 RTS# Output Request to Send Control Output / Handshake Signal. 5 RXD Input Receiving Asynchronous Data Input. Ring Indicator Control Input. When remote wake up is enabled in the 6 RI# Input internal EEPROM taking RI# low (20ms active low pulse) can be used to resume the PC USB host controller from suspend. 9 DSR# Input Data Set Ready Control Input / Handshake Signal. 10 DCD# Input Data Carrier Detect Control Input. 11 CTS# Input Clear To Send Control Input / Handshake Signal. Configurable CBUS output only Pin. Function of this pin is configured in 12 CBUS4 I/O the device internal EEPROM. Factory default configuration is SLEEP#. See CBUS Signal Options, Table 3.9. Configurable CBUS I/O Pin. Function of this pin is configured in the 13 CBUS2 I/O device internal EEPROM. Factory default configuration is TXDEN. See CBUS Signal Options, Table 3.9. Configurable CBUS I/O Pin. Function of this pin is configured in the device internal EEPROM. Factory default configuration is PWREN#. See 14 CBUS3 I/O CBUS Signal Options, Table 3.9. PWREN# should be used with a 10kΩ resistor pull up. Configurable CBUS I/O Pin. Function of this pin is configured in the 22 CBUS1 I/O device internal EEPROM. Factory default configuration is RXLED#. See CBUS Signal Options, Table 3.9. Configurable CBUS I/O Pin. Function of this pin is configured in the 23 CBUS0 I/O device internal EEPROM. Factory default configuration is TXLED#. See CBUS Signal Options, Table 3.9. Table 3.4 UART Interface and CUSB Group (see note 3)Notes: 1. The minimum operating voltage VCC must be +4.0V (could use VBUS=+5V) when using the internal clock generator. Operation at +3.3V is possible using an external crystal oscillator. 2. For details on how to use an external crystal, ceramic resonator, or oscillator with the FT232R, please refer Section 7.6
3. When used in Input Mode, the input pins are pulled to VCCIO via internal 200kΩ resistors. These pins can be programmed to gently pull low during USB suspend (PWREN# = “1”) by setting an option in the internal EEPROM.