Rainbow Electronics AT90S8515 - Manual (Page 28)

28
AT90S8515
0841G–09/01
Timer/Counter Interrupt Flag
Register – TIFR
• Bit 7 – TOV1: Timer/Counter1 Overflow Flag
The TOV1 is set (one) when an overflow occurs in Timer/Counter1. TOV1 is cleared by
hardware when executing the corresponding interrupt handling vector. Alternatively,
TOV1 is cleared by writing a logical “1” to the flag. When the I-bit in SREG, TOIE1
(T i m e r / C o u n t e r 1 O v e rf l o w I n t e rr u p t E n a b l e ) a n d T OV 1 a r e s e t ( o n e ), t h e
Timer/Counter1 Overflow interrupt is executed. In PWM mode, this bit is set when
Timer/Counter1 changes counting direction at $0000.
• Bit 6 – OCF1A: Output Compare Flag 1A
The OCF1A bit is set (one) when compare match occurs between the Timer/Counter1
and the data in OCR1A (Output Compare Register 1A). OCF1A is cleared by hardware
when executing the corresponding interrupt handling vector. Alternatively, OCF1A is
cleared by writing a logical “1” to the flag. When the I-bit in SREG, OCIE1A
(Timer/Counter1 Compare Match InterruptA Enable) and the OCF1A are set (one), the
Timer/Counter1 CompareA Match interrupt is executed.
• Bit 5 – OCF1B: Output Compare Flag 1B
The OCF1B bit is set (one) when compare match occurs between the Timer/Counter1
and the data in OCR1B (Output Compare Register 1B). OCF1B is cleared by hardware
when executing the corresponding interrupt handling vector. Alternatively, OCF1B is
cleared by writing a logical “1” to the flag. When the I-bit in SREG, OCIE1B
(Timer/Counter1 Compare Match InterruptB Enable) and the OCF1B are set (one), the
Timer/Counter1 CompareB Match interrupt is executed.
• Bit 4 – Res: Reserved Bit
This bit is a reserved bit in the AT90S8515 and always reads zero.
• Bit 3 – ICF1: Input Capture Flag 1
The ICF1 bit is set (one) to flag an input capture event, indicating that the
Timer/Counter1 value has been transferred to the input capture register (ICR1). ICF1 is
cleared by hardware when executing the corresponding interrupt handling vector. Alter-
natively, ICF1 is cleared by writing a logical “1” to the flag. When the SREG I-bit, TICIE1
(Timer/Counter1 Input Capture Interrupt Enable) and ICF1 are set (one), the
Timer/Counter1 Capture interrupt is executed.
• Bit 2 – Res: Reserved Bit
This bit is a reserved bit in the AT90S8515 and always reads zero.
• Bit 1 – TOV: Timer/Counter0 Overflow Flag
The bit TOV0 is set (one) when an overflow occurs in Timer/Counter0. TOV0 is cleared
by hardware when executing the corresponding interrupt handling vector. Alternatively,
TOV0 is cleared by writing a logical “1” to the flag. When the SREG I-bit, TOIE0
(T i m e r / C o u n t e r 0 O v e rf l o w I n t e rr u p t E n a b l e ) a n d T OV 0 a r e s e t ( o n e ), t h e
Timer/Counter0 Overflow interrupt is executed.
• Bit 0 – Res: Reserved Bit
This bit is a reserved bit in the AT90S8515 and always reads zero.
Bit 7 6 5 4 3 2 1 0
$38 ($58) TOV1 OCF1A OCIFB – ICF1 – TOV0 – TIFR
Read/Write R/W R/W R/W R R/W R R/W R
Initial Value 0 0 0 0 0 0 0 0