XA-C3 Datasheet, PDF (22/68 Pages) NXP Semiconductors – XA 16-bit microcontroller family 32K/1024 OTP CAN transport layer controller 1 UART, 1 SPI Port, CAN 2.0B, 32 CAN ID Filters, transport layer co-proce

Philips Semiconductors
XA 16-bit microcontroller family
32K/1024 OTP CAN transport layer controller
1 UART, 1 SPI Port, CAN 2.0B, 32 CAN ID filters, transport layer co-processor
Preliminary specification
XA-C3
timer register is loaded with FFFF hex. The underflow also sets the
TF2 flag, which can generate an interrupt if enabled.
The External flag EXF2 bit toggles when Timer 2 underflows or
overflows. This EXF2 bit can be used as a 17th bit of resolution, if
needed. the EXF2 bit flag does not generate an interrupt in this
mode. As the baud rate generator, timer T2 is incremented by TCLK.
Baud Rate Generator Mode
By setting the TCLK0 and/or RCLK0 in T2CON, Timer 2 can be
chosen as the baud rate generator for the Transmitter and/or
Receiver sides of UART–0.
Programmable Clock-Out
A 50% duty cycle clock can be programmed to come out on P1.6.
This pin, besides being a regular I/O pin, has two alternate
functions. Either it can be programmed to input the External clock for
Timer/Counter 2 or to output a 50% duty cycle clock.
Table 7. Timer 2 Operating Modes
Bits of Special Function Registers
TR2
CP or RL2/
RCLK0 or TCLK0
T2CON[2] T2CON[0] T2CON[5] or T2CON[4]
0
X
X
1
0
0
1
0
0
1
1
0
1
X
1
DCEN
T2MOD[0]
X
0
1
X
X
To configure the Timer/Counter 2 as a clock generator, bit {C2 or
T2/} (T2CON[1]) must be cleared and bit T2OE (T2MOD[1]) must be
set. Bit TR2 (T2CON[2]) also must be set to start the timer.
The Clock–Out frequency depends on the oscillator frequency and
the reload value of Timer 2 capture registers (TCAP2H, TCAP2L) as
shown in this equation:
TCLK
2 (65536–TCAP2H, TCAP2L)
In the Clock–Out mode Timer 2 roll–overs will not generate an
interrupt. This is similar to when it is used as a baud–rate generator.
It is possible to use Timer 2 as a baud–rate generator and a clock
generator simultaneously. Note, however, that the baud–rate will be
1/8 of the Clock–Out frequency.
MODE
Timer off (stopped)
16–bit auto–reload, counting up
16–bit auto–reload, counting up or down depending on T2EX pin
16–bit capture
Baud rate generator
TSTAT
Address:411
Bit Addressable
Reset Value: 00H
MSB
LSB
—
—
—
—
— T1OE — T0OE
BIT
TSTAT.2
TSTAT.0
SYMBOL
T1OE
T0OE
FUNCTION
When 0, this bit allows the T1 pin to clock Timer 1 when in the counter mode.
When 1, T1 acts as an output and toggles at every Timer 1 overflow.
When 0, this bit allows the T0 pin to clock Timer 0 when in the counter mode.
When 1, T0 acts as an output and toggles at every Timer 0 overflow.
SU00612B
Figure 9. Timer 0 and 1 Extended Status (TSTAT)
T2MOD
Address:419
Bit Addressable
Reset Value: 00H
MSB
—
— RCLK1 TCLK1 —
LSB
— T2OE DCEN
BIT
T2MOD.5
T2MOD.4
T2MOD.1
T2MOD.0
SYMBOL
RCLK1
TCLK1
T2OE
DCEN
FUNCTION
Receive Clock Flag.
Transmit Clock Flag. RCLK1 and TCLK1 are used to select Timer 2 overflow rate as a clock source
for UART1 instead of Timer T1.
When 0, this bit allows the T2 pin to clock Timer 2 when in the counter mode.
When 1, T2 acts as an output and toggles at every Timer 2 overflow.
Controls count direction for Timer 2 in autoreload mode.
DCEN=0 counter set to count up only
DCEN=1 counter set to count up or down, depending on T2EX (see text).
SU00610B
Figure 10. Timer 2 Mode Control (T2MOD)
2000 Jan 25
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