Intel 8XC196NT, User Manual

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8XC196NT USER’S MANUAL
B-12
T1CLK I Timer 1 External Clock
External clock for timer 1. Timer 1 increments (or decrements) on both rising
and falling edges of T1CLK. Also used in conjunction with T1DIR for quadrature
counting mode.
and
External clock for the serial I/O baud-rate generator input (program selectable).
T1CLK is multiplexed with P6.2.
T2CLK I Timer 2 External Clock
External clock for timer 2. Timer 2 increments (or decrements) on both rising
and falling edges of T2CLK. Also used in conjunction with T2DIR for quadrature
counting mode.
T2CLK is multiplexed with P1.0 and EPA0.
T1DIR I Timer 1 External Direction
External direction (up/down) for timer 1. Timer 1 increments when T1DIR is high
and decrements when it is low. Also used in conjunction with T1CLK for
quadrature counting mode.
T1DIR is multiplexed with P6.3.
T2DIR I Timer 2 External Direction
External direction (up/down) for timer 2. Timer 2 increments when T2DIR is high
and decrements when it is low. Also used in conjunction with T2CLK for
quadrature counting mode.
T2DIR is multiplexed with P1.2 and EPA2.
TXD O Transmit Serial Data
In serial I/O modes 1, 2, and 3, TXD transmits serial port output data. In mode
0, it is the serial clock output.
TXD is multiplexed with P2.0 and PVER.
V
CC
PWR Digital Supply Voltage
Connect each V
CC
pin to the digital supply voltage.
V
PP
PWR Programming Voltage
During programming, the V
PP
pin is typically at +12.5 V (V
PP
voltage).
Exceeding the maximum V
PP
voltage specification can damage the device.
V
PP
also causes the device to exit powerdown mode when it is driven low for at
least 50 ns. Use this method to exit powerdown only when using an external
clock source because it enables the internal phase clocks, but not the internal
oscillator. See “Driving the Vpp Pin Low” on page 13-5.
On devices with no internal nonvolatile memory, connect V
PP
to V
CC
.
V
REF
PWR Reference Voltage for the A/D Converter
This pin also supplies operating voltage to both the analog portion of the A/D
converter and the logic used to read port 0.
V
SS
GND Digital Circuit Ground
Connect each V
SS
pin to ground through the lowest possible impedance path.
Table B-4. Signal Descriptions (Continued)
Name Type Description