C8051F321 Silicon Laboratories Inc, C8051F321 Datasheet - Page 220

• Manufacturer Part Number: C8051F321
• Description: IC 8051 MCU 16K FLASH 28MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F32xr

Specifications of C8051F321

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 21
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

C8051F320/1
19.1.4. 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 settings. 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.
220
/INT0
T0
Crossbar
Pre-scaled Clock
SYSCLK
IN0PL
GATE0
XOR
Figure 19.3. T0 Mode 3 Block Diagram
0
1
TR0
M
H
T
3
M
T
3
L
CKCON
M
H
T
2
0
1
M
T
2
L
M
T
1
M
T
0
C
S
A
1
C
S
A
0
Rev. 1.1
TR1
G
A
T
E
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