C8051F566-IQR Silicon Labs, C8051F566-IQR Datasheet - Page 277

• Manufacturer Part Number: C8051F566-IQR
• Description: 8-bit Microcontrollers - MCU 50 MIPS 16 kB 2 kB LIN 2.1 SPI
• Manufacturer: Silicon Labs

Specifications of C8051F566-IQR

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

26. 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 six 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 six 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
“26.3. Capture/Compare Modules” on page 279). 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 26.1
Important Note: The PCA Module 5 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 26.4 for details.
Capture/Compare
Module 0
SYSCLK/12
SYSCLK/4
Timer 0 Overflow
ECI
SYSCLK
External Clock/8
Capture/Compare
Module 1
CLOCK
MUX
PCA
Figure 26.1. PCA Block Diagram
16-Bit Counter/Timer
Capture/Compare
Module 2
Crossbar
Rev. 1.1
Port I/O
Capture/Compare
Module 3
C8051F55x/56x/57x
Capture/Compare
Module 4
Capture/Compare
Module 5 / WDT
277