73S1217F Datasheet, PDF (59/140 Pages) Teridian Semiconductor Corporation – Bus-Powered 80515 System-on-Chip with USB, ISO 7816 / EMV, PINpad and More

DS_1217F_002
73S1217F Data Sheet
1.7.12 LED Driver
The 73S1217F provides a single dedicated output pin for driving an LED. The LED driver pin can be
configured as a current source that will pull to ground to drive an LED that is connected to VDD without
the need for an external current limiting resistor. This pin may be used as general purpose output with
the programmed pull-down current and a strong (CMOS) pull-up, if enabled. The analog block must be
enabled when this output is being used to drive the selected output current.
This pin may be used as an input with consideration of the programmed output current and level. The
register bit when read, indicates the state of the pin.
LED Control Register (LEDCtl): 0xFFF3 Å 0xFF
MSB
–
Table 61: The LEDCtl Register
LSB
LPUEN ISET.1 ISET.0 LEDD3 LEDD2 LEDD 1 LEDD0
Bit
LEDCtl.7
LEDCtl.6
LEDCtl.5
LEDCtl.4
LEDCtl.3
LEDCtl.2
LEDCtl.1
LEDCtl.0
Symbol
–
LPUEN
ISET.1
ISET.0
–
–
–
LEDD0
Function
0 = Pull-up is enabled for the LED pin.
These two bits control the drive current (to ground) for the LED driver pin.
Current levels are:
00 = 0ma(off)
01 = 2ma
10 = 4ma
11 = 10ma
Write data controls output level of pin LED0. Read will report level of pin LED0.
Rev. 1.2
59