AT91SAM9G45-CU-999 Atmel, AT91SAM9G45-CU-999 Datasheet - Page 111

• Manufacturer Part Number: AT91SAM9G45-CU-999
• Description: IC MCU ARM9 APMC 324TFBGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM9G45-CU-999

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 400MHz
• Connectivity: EBI/EMI, Ethernet, I²C, IrDA, MMC, SPI, SSC, UART/USART, USB
• Peripherals: AC'97, DMA, I²S, LCD, POR, PWM, WDT
• Number Of I /o: 160
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: ROM
• Ram Size: 128K x 8
• Voltage - Supply (vcc/vdd): 0.9 V ~ 1.1 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 324-TFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed

15. Periodic Interval Timer (PIT)
15.1
15.2
15.3
Figure 15-1. Periodic Interval Timer
15.4
6438F–ATARM–21-Jun-10
Prescaler
MCK
Description
Embedded Characteristics
Block Diagram
Functional Description
MCK/16
The Periodic Interval Timer (PIT) provides the operating system’s scheduler interrupt. It is
designed to offer maximum accuracy and efficient management, even for systems with long
response time.
The Periodic Interval Timer aims at providing periodic interrupts for use by operating systems.
The PIT provides a programmable overflow counter and a reset-on-read feature. It is built
around two counters: a 20-bit CPIV counter and a 12-bit PICNT counter. Both counters work at
Master Clock /16.
• Includes a 20-bit Periodic Counter, with less than 1μs accuracy
• Includes a 12-bit Interval Overlay Counter
• Real Time OS or Linux/WinCE compliant tick generator
Counter
0
CPIV
CPIV
20-bit
0
1
PIT_PIVR
PIT_PIIR
PIT_MR
= ?
PIV
0
0
PICNT
Adder
12-bit
PICNT
1
PIT_SR
AT91SAM9G45
read PIT_PIVR
PITS
set
reset
PIT_MR
PITIEN
pit_irq
111