C8051F046-GQ Silicon Laboratories Inc, C8051F046-GQ Datasheet - Page 289

• Manufacturer Part Number: C8051F046-GQ
• Description: IC 8051 MCU 32K FLASH 100TQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F04xr

Specifications of C8051F046-GQ

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: CAN, EBI/EMI, SMBus (2-Wire/I²C), SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 64
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 4.25K 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: 100-TQFP, 100-VQFP
• Processor Series: C8051F0x
• Core: 8051
• Data Bus Width: 8 bit
• Data Ram Size: 4.25 KB
• Interface Type: CAN, SMBus, SPI, UART
• Maximum Clock Frequency: 25 MHz
• Number Of Programmable I/os: 64
• Number Of Timers: 5
• Operating Supply Voltage: 2.7 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: PK51, CA51, A51, ULINK2
• Development Tools By Supplier: C8051F040DK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 13 Channel
• On-chip Dac: 12 bit, 2 Channel
• Package: 100TQFP
• Device Core: 8051
• Family Name: C8051F04x
• Maximum Speed: 25 MHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: 336-1211

23. Timers
Each MCU includes 5 counter/timers: Timer 0 and Timer 1 are 16-bit counter/timers compatible with those
found in the standard 8051. Timer 2, Timer 3, and Timer 4 are 16-bit auto-reload and capture counter/tim-
ers for use with the ADC, DAC’s, square-wave generation, or for general-purpose use. These timers can
be used to measure time intervals, count external events and generate periodic interrupt requests. Timer 0
and Timer 1 are nearly identical and have four primary modes of operation. Timers 2, 3, and 4 are identi-
cal, and offer not only 16-bit auto-reload and capture, but have the ability to produce a 50% duty-cycle
square-wave (toggle output) at an external port pin.
Timers 0 and 1 may be clocked by one of five sources, determined by the Timer Mode Select bits (T1M-
T0M) and the Clock Scale bits (SCA1-SCA0). The Clock Scale bits define a pre-scaled clock by which
Timer 0 and/or Timer 1 may be clocked (See SFR Definition 23.3 for pre-scaled clock selection). Timer 0/1
may then be configured to use this pre-scaled clock signal or the system clock. Timers 2, 3, and 4 may be
clocked by the system clock, the system clock divided by 12, or the external oscillator clock source divided
by 8.
Timer 0 and Timer 1 may also be operated as counters. When functioning as a counter, a counter/timer
register is incremented on each high-to-low transition at the selected input pin. Events with a frequency of
up to one-fourth the system clock's frequency can be counted. The input signal need not be periodic, but it
should be held at a given logic level for at least two full system clock cycles to ensure the level is properly
sampled.
23.1. Timer 0 and Timer 1
Each timer is implemented as 16-bit register accessed as two separate bytes: a low byte (TL0 or TL1) and
a high byte (TH0 or TH1). The Counter/Timer Control register (TCON) is used to enable Timer 0 and Timer
1 as well as indicate their status. Timer 0 interrupts can be enabled by setting the ET0 bit in the IE register
(Section “12.3.5. Interrupt Register Descriptions” on page
setting the ET1 bit in the IE register
modes selected by setting the Mode Select bits T1M1-T0M0 in the Counter/Timer Mode register (TMOD).
Each timer can be configured independently.
23.1.1. Mode 0: 13-bit Counter/Timer
Timer 0 and Timer 1 operate as 13-bit counter/timers in Mode 0. The following describes the configuration
and operation of Timer 0. However, both timers operate identically, and Timer 1 is configured in the same
manner as described for Timer 0.
The TH0 register holds the eight MSBs of the 13-bit counter/timer. TL0 holds the five LSBs in bit positions
TL0.4-TL0.0. The three upper bits of TL0 (TL0.7-TL0.5) are indeterminate and should be masked out or
ignored when reading. As the 13-bit timer register increments and overflows from 0x1FFF (all ones) to
0x0000, the timer overflow flag TF0 (TCON.5) is set and an interrupt will occur if Timer 0 interrupts are
enabled.
Two 8-bit counter/timers (Timer 0 only)
8-bit counter/timer with auto-reload
Timer 0 and Timer 1 Modes:
13-bit counter/timer
16-bit counter/timer
(Section
12.3.5). Both counter/timers operate in one of four primary
Rev. 1.5
C8051F040/1/2/3/4/5/6/7
16-bit counter/timer with auto-reload
16-bit counter/timer with capture
156); Timer 1 interrupts can be enabled by
Timer 2, 3, and 4 Modes:
Toggle Output
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