FT2232L Dual USB UART / FIFO I.C.
5.0
Pin Definitions
This section decribes the operation of the FT2232L pins. Common pins are defined in the first section, then the I/O
pins are defined, by chip mode. More detailed descriptions of the operation of the I/O pins are provided in section 9.
5.1
Common Pins
The operation of the following FT2232L pins stay the same, regardless of the chip mode :-
USB INTERFACE GROUP
Pin#
7
8
Signal
USBDP
USBDM
Type
I/O
I/O
Description
USB Data Signal Plus ( Requires 1.5K pull-up to 3V3OUT or RSTOUT# )
USB Data Signal Minus
EEPROM INTERFACE GROUP
Pin#
48
1
2
Signal
EECS
EESK
EEDATA
Type
I/O
I/O
Description
EEPROM – Chip Select. Tri-State during device reset.
**Note 1
EEPROM – Data I/O Connect directly to Data-In of the EEPROM and to Data-
Out of the EEPROM via a 2.2K resistor. Also, pull Data-Out of the EEPROM
to VCC via a 10K resistor for correct operation. Tri-State during device reset.
**Note 1
OUTPUT Clock signal to EEPROM. Tri-State during device reset, else drives out.
**Note 1
MISCELLANEOUS SIGNAL GROUP
Pin#
4
5
Signal
RESET#
RSTOUT#
Type
INPUT
Description
Can be used by an external device to reset the FT2232L. If not required, tie to
VCC.
**Note 1
OUTPUT Output of the internal Reset Generator. Drives low for 5.6 ms after VCC > 3.5V
and the internal clock starts up, then clamps it’s output to the 3.3V output of the
internal regulator. Taking RESET# low will also force RSTOUT# to drive low.
RSTOUT# is NOT affected by a USB Bus Reset.
INPUT
Puts device into I.C. test mode – must be tied to GND for normal operation.
OUTPUT Goes Low after the device is configured via USB, then high during USB suspend.
Can be used to control power to external logic using a P-Channel Logic Level
MOSFET switch. Enable the Interface Pull-Down Option in EEPROM when using
the PWREN# pin in this way.
INPUT
Input to 6MHz Crystal Oscillator Cell. This pin can also be driven by an external
6MHz clock if required. Note : Switching threshold of this pin is VCC/2, so if
driving from an external source, the source must be driving at 5V CMOS level or
a.c. coupled to centre around VCC/2.
47
41
TEST
PWREN#
43
XTIN
44
XTOUT
OUTPUT Output from 6MHz Crystal Oscillator Cell. XTOUT stops oscillating during USB
suspend, so take care if using this signal to clock external logic.
**Note 1 -
During device reset, these pins are tri-state but pulled up to VCC via internal 200K resistors.
DS2232L Version 1.4
© Future Technology Devices International Ltd. 2005 Page 10 of 51
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