C8051F709-GQR Silicon Labs, C8051F709-GQR Datasheet - Page 284

• Manufacturer Part Number: C8051F709-GQR
• Description: 8-bit Microcontrollers - MCU 8kB 32B EEPROM Cap Sense
• Manufacturer: Silicon Labs

Specifications of C8051F709-GQR

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

C8051F70x/71x
34. Programmable Counter Array
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. The counter/timer is driven by a
programmable timebase that can select between seven sources: system clock, system clock divided by
four, system clock divided by twelve, the external oscillator clock source divided by 8, Timer 0 overflows, or
an external clock signal on the ECI input pin. Each capture/compare module may be configured to operate
independently in one of six modes: Edge-Triggered Capture, Software Timer, High-Speed Output, Fre-
quency Output, 8 to 11-Bit PWM, or 16-Bit PWM (each mode is described in Section
“34.3. Capture/Compare Modules” on page 286). The external oscillator clock option is ideal for real-time
clock (RTC) functionality, allowing the PCA to be clocked by a precision external oscillator while the inter-
nal oscillator drives the system clock. The PCA is configured and controlled through the system controller's
Special Function Registers. The PCA block diagram is shown in Figure 34.1
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Capture/Compare
Figure 34.1. PCA Block Diagram
Module 0
SYSCLK/12
SYSCLK/4
Timer 0 Overflow
SYSCLK
External Clock/8
ECI
Crossbar
Port I/O
Rev. 1.0
Capture/Compare
Module 1
CLOCK
MUX
PCA
16-Bit Counter/Timer
Capture/Compare
Module 2