ARM VERSION 1.2 Arkusz Danych Pobierz pdf (Strona 48)

ARMulator Basics

2.10.4 Timer

The timer is an implementation of the reference timer. It provides two counter-timers.

For details see Timer on page 4-77.

The configuration of the timer model is controlled by a section in

peripherals.ami

. It

has the following items:

{Default_Timer=Timer

Range:Base=0x0a800000

;Frequency of clock to controller.

CLK=20000000

;; Interrupt controller source bits - 4 and 5 as standard

IntOne=4

IntTwo=5

WAITS=0

}

Range:Base

specifies the area in memory into which the timer registers are mapped. For

details of the interrupt controller registers, see Timer on page 4-77.

CLK

is used to specify the clock rate of the peripheral. This is usually the same as the

processor clock rate.

IntOne

specifies the interrupt line connection to the interrupt controller for timer 1

interrupts.

IntTwo

specifies the interrupt line connection to the interrupt controller for

timer 2 interrupts.

WAITS

specifies the number of wait states that accessing the timer imposes on the

processor. The maximum is 30.

1 2 ... 43 44 45 46 47 48 49 50 51 52 53 ... 175 176

Brak uwag

ARM VERSION 1.2 Arkusz Danych Strona 48