USB-1808X-OEM User's Guide
Specifications
23
Timer
Table 13. Timer specifications
Parameter
Specification
Terminal name
TMR0, TMR1
Timer type
PWM output with count, period, delay, and pulse width registers
Output value
Default state is idle low with pulses high, software-selectable output invert
Trigger source
OTRIG (see
Internal clock frequency
100 MHz
Register widths
32-bit
High pulse width
10 ns min
Low pulse width
10 ns min
Output high voltage
4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –2.5 mA)
Output low voltage
0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 2.5 mA)
Output current
±2.5 mA max
External clock input/output
Table 14. External clock I/O specifications
Parameter
Specification
Terminal names
ICLKI, ICLKO
OCLKI, OCLKO
Terminal types
xCLKI:
Input, active on rising edge
xCLKO:
Output, power on default is 0 V, active on rising edge
Terminal descriptions
xCLKI:
Receives sampling clock from external source
xCLKO:
Outputs the internal input scan or internal output scan clock, or the
pulse generated from xCLKI when in external clock mode.
Input clock rate
500 kHz max
Clock pulse width
xCLKI:
400 ns min
xCLKO:
400 ns min
Input type
Schmitt trigger, 33
Ω series resistor, 47
kΩ
pull-down to ground
Schmitt trigger hysteresis
0.4 V to 1.2 V
Input high voltage
2.2 V min
5.5 V absolute max
Input low voltage
1.5 V max
–0.5 V absolute min
0 V recommended min
Output high voltage
4.4 V min (IOH = –50 µA)
3.76 V min (IOH = –2.5 mA)
Output low voltage
0.1 V max (IOL = 50 µA)
0.44 V max (IOL = 2.5 mA)
Output current
±2.5 mA max
