AT90LS4433-4AI datasheet(63/126 Pages) ATMEL

63 / 126 page

AT90S/LS4433

1042H–AVR–04/03

• Bit 4 – ACI: Analog Comparator Interrupt Flag

This bit is set (one) when a comparator output event triggers the interrupt mode defined

by ACI1 and ACI0. The Analog Comparator Interrupt routine is executed if the ACIE bit

is set (one) and the I-bit in SREG is set (one). ACI is cleared by hardware when execut-

ing the corresponding interrupt handling vector. Alternatively, ACI is cleared by writing a

logical “1” to the flag.

• Bit 3 – ACIE: Analog Comparator Interrupt Enable

When the ACIE bit is set (one) and the I-bit in the Status Register is set (one), the Ana-

log Comparator interrupt is activated. When cleared (zero), the interrupt is disabled.

• Bit 2 – ACIC: Analog Comparator Input Capture Enable

When set (one), this bit enables the Input Capture function in Timer/Counter1 to be trig-

gered by the Analog Comparator. The comparator output is, in this case, directly

connected to the Input Capture front-end logic, making the comparator utilize the noise

canceler and edge select features of the Timer/Counter1 Input Capture interrupt. When

cleared (zero), no connection between the Analog Comparator and the Input Capture

function is given. To make the comparator trigger the Timer/Counter1 Input Capture

interrupt, the TICIE1 bit in the Timer Interrupt Mask Register (TIMSK) must be set (one).

• Bits 1, 0 – ACIS1, ACIS0: Analog Comparator Interrupt Mode Select

These bits determine which comparator events trigger the Analog Comparator interrupt.

The different settings are shown in Table 20.

Note:

1. When changing the ACIS1/ACIS0 bits, the Analog Comparator interrupt must be dis-

abled by clearing its Interrupt Enable bit in the ACSR Register. Otherwise, an

interrupt can occur when the bits are changed.

Caution: Using the SBI or CBI instruction on bits other than ACI in this register will write

a one back into ACI if it is read as set, thus clearing the flag.

Table 20. ACIS1/ACIS0 Settings

(1)

ACIS1

ACIS0

Interrupt Mode

Comparator Interrupt on Output Toggle.

Reserved

Comparator Interrupt on Falling Output Edge.

Comparator Interrupt on Rising Output Edge.

AT90LS4433-4AI датащи(PDF) 63 Page - ATMEL Corporation