UPSD3234AV-24U1T STMicroelectronics, UPSD3234AV-24U1T Datasheet - Page 53

• Manufacturer Part Number: UPSD3234AV-24U1T
• Description: Flash Programmable System Devices with 8032 Microcontroller Core and 64Kbit SRAM
• Manufacturer: STMicroelectronics

www.DataSheet4U.com
Mode 2. Mode 2 configures the Timer register as
an 8-bit Counter (TL1) with automatic reload, as
shown in
not only sets TF1, but also reloads TL1 with the
contents of TH1, which is preset by software. The
reload leaves TH1 unchanged. Mode 2 operation
is the same for Timer/Counter 0.
Mode 3. Timer 1 in Mode 3 simply holds its count.
The effect is the same as setting TR1 = 0.
Timer 0 in Mode 3 establishes TL0 and TH0 as two
separate counters. The logic for Mode 3 on Timer
0 is shown in
Timer 0 control Bits: C/T, GATE, TR0, INT0, and
TF0. TH0 is locked into a timer function (counting
machine cycles) and takes over the use of TR1
and TF1 from Timer 1. Thus, TH0 now controls the
“Timer 1“ Interrupt.
Mode 3 is provided for applications requiring an
extra 8-bit timer on the counter. With Timer 0 in
Mode 3, an uPSD323X Devices can look like it has
three Timer/Counters. When Timer 0 is in Mode 3,
Timer 1 can be turned on and off by switching it out
of and into its own Mode 3, or can still be used by
the serial port as a baud rate generator, or in fact,
in any application not requiring an interrupt.
Timer 2
Like Timers 0 and 1, Timer 2 can operate as either
an event timer or as an event counter. This is se-
lected by Bit C/T2 in the special function register
T2CON. It has three operating modes: capture,
autoload, and baud rate generator, which are se-
Table 40. Timer/Counter 2 Control Register (T2CON)
TF2
7
Figure 23., page
Figure 24., page
EXF2
6
51. Overflow from TL1
RCLK
5
52. TL0 uses the
uPSD3234A, uPSD3234BV, uPSD3233B, uPSD3233BV
TCLK
4
lected by bits in the T2CON as shown in
41., page
options which are selected by Bit EXEN2 in
T2CON. if EXEN2 = 0, then Timer 2 is a 16-bit tim-
er or counter which upon overflowing sets Bit TF2,
the Timer 2 Overflow Bit, which can be used to
generate an interrupt. If EXEN2 = 1, then Timer 2
still does the above, but with the added feature
that a 1-to-0 transition at external input T2EX
causes the current value in the Timer 2 registers,
TL2 and TH2, to be captured into registers
RCAP2L and RCAP2H, respectively. In addition,
the transition at T2EX causes Bit EXF2 in T2CON
to be set, and EXF2 like TF2 can generate an in-
terrupt. The Capture Mode is illustrated in
25., page
In the Auto-reload Mode, there are again two op-
tions, which are selected by bit EXEN2 in T2CON.
If EXEN2 = 0, then when Timer 2 rolls over it not
only sets TF2 but also causes the Timer 2 regis-
ters to be reloaded with the 16-bit value in regis-
ters RCAP2L and RCAP2H, which are preset by
software. If EXEN2 = 1, then Timer 2 still does the
above, but with the added feature that a 1-to-0
transition at external input T2EX will also trigger
the 16-bit reload and set EXF2. The Auto-reload
Mode is illustrated in Standard Serial Interface
(UART)
eration Mode is selected by (RCLK, RCLK1)=1
and/or (TCLK, TCLK1)=1. It will be described in
conjunction with the serial port.
EXEN2
3
Figure 26., page
54. In the Capture Mode there are two
55.
TR2
2
55. The Baud Rate Gen-
C/T2
1
CP/RL2
0
Figure
53/170
Table