C8051F521-IMR Silicon Labs, C8051F521-IMR Datasheet - Page 195

• Manufacturer Part Number: C8051F521-IMR
• Description: 8-bit Microcontrollers - MCU 8KB 12ADC 125C 10Pin MCU
• Manufacturer: Silicon Labs

Specifications of C8051F521-IMR

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: 8051
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 25 MHz
• Program Memory Size: 8 KB
• Data Ram Size: 256 B
• On-chip Adc: Yes
• Package / Case: DFN-10
• Mounting Style: SMD/SMT
• A/d Bit Size: 12 bit
• A/d Channels Available: 6
• Interface Type: SPI, UART
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 6
• Number Of Timers: 3
• On-chip Dac: No
• Processor Series: C8051
• Program Memory Type: Flash
• Factory Pack Quantity: 1500
• Supply Voltage - Max: 2.7 V, 5.25 V
• Supply Voltage - Min: 2 V, 2.7 V

19. Programmable Counter Array (PCA0)
The Programmable Counter Array (PCA0) provides enhanced timer functionality while requiring less CPU
intervention than the standard 8051 counter/timers. The PCA consists of a dedicated 16-bit counter/timer
and three 16-bit capture/compare modules. Each capture/compare module has its own associated I/O line
(CEXn) which is routed through the Crossbar to Port I/O when enabled (See Section “13.1. Priority Cross-
bar Decoder” on page 122 for details on configuring the Crossbar). The counter/timer is driven by a pro-
grammable timebase that can select between six sources: system clock, system clock divided by four,
system clock divided by twelve, the external oscillator clock source divided by 8, Timer 0 overflow, or an
external clock signal on the ECI input pin. Each capture/compare module may be configured to operate
independently in one of three modes: Edge-Triggered Capture, Software Timer, High-Speed Output, Fre-
quency Output, 8-Bit PWM, or 16-Bit PWM (each mode is described in Section “19.2. Capture/Compare
Modules” on page 197). The PCA is configured and controlled through the system controller's Special
Function Registers. The PCA block diagram is shown in Figure 19.1
Important Note: The PCA Module 2 may be used as a watchdog timer (WDT), and is enabled in this mode
following a system reset. Access to certain PCA registers is restricted while WDT mode is enabled.
See Section “19.3. Watchdog Timer Mode” on page 203 for details.
SYSCLK/12
Timer 0 Overflow
SYSCLK
External Clock/8
SYSCLK/4
ECI
Figure 19.1. PCA Block Diagram
Capture/Compare
Module 0
CLOCK
MUX
PCA
Crossbar
Rev. 1.4
Port I/O
16-Bit Counter/Timer
Capture/Compare
Module 1
C8051F52x/F53x
Capture/Compare
Module 2
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