C8051F34A-GMR Silicon Labs, C8051F34A-GMR Datasheet - Page 238

• Manufacturer Part Number: C8051F34A-GMR
• Description: 8-bit Microcontrollers - MCU 48 MIPS 64KB 10ADC
• Manufacturer: Silicon Labs

Specifications of C8051F34A-GMR

• Rohs: yes
• Core: 8051
• Processor Series: C8051
• Data Bus Width: 8 bit

C8051F340/1/2/3/4/5/6/7/8/9/A/B/C/D
21.1.4. Mode 3: Two 8-bit Counter/Timers (Timer 0 Only)
In Mode 3, Timer 0 is configured as two separate 8-bit counter/timers held in TL0 and TH0. The counter/
timer in TL0 is controlled using the Timer 0 control/status bits in TCON and TMOD: TR0, C/T0, GATE0 and
TF0. TL0 can use either the system clock or an external input signal as its timebase. The TH0 register is
restricted to a timer function sourced by the system clock or prescaled clock. TH0 is enabled using the
Timer 1 run control bit TR1. TH0 sets the Timer 1 overflow flag TF1 on overflow and thus controls the
Timer 1 interrupt.
Timer 1 is inactive in Mode 3. When Timer 0 is operating in Mode 3, Timer 1 can be operated in Modes 0,
1 or 2, but cannot be clocked by external signals nor set the TF1 flag and generate an interrupt. However,
the Timer 1 overflow can be used to generate baud rates for the SMBus and/or UART, and/or initiate ADC
conversions. While Timer 0 is operating in Mode 3, Timer 1 run control is handled through its mode set-
tings. To run Timer 1 while Timer 0 is in Mode 3, set the Timer 1 Mode as 0, 1, or 2. To disable Timer 1,
configure it for Mode 3.
238
INT0
T0
Crossbar
Pre-scaled Clock
SYSCLK
IN0PL
GATE0
Figure 21.3. T0 Mode 3 Block Diagram
XOR
0
1
TR0
M
H
T
3
T
M
3
L
CKCON
M
H
T
2
0
1
M
T
2
L
M
T
1
M
T
0
S
C
A
1
S
C
A
0
Rev. 1.3
TR1
G
A
E
T
1
C
T
1
/
M
T
1
1
TMOD
M
T
1
0
G
A
T
E
0
C
T
0
/
M
T
0
1
M
T
0
0
(8 bits)
(8 bits)
TH0
TL0
TF1
TR1
TF0
TR0
IE1
IT1
IE0
IT0
Interrupt
Interrupt