at90ls8535-8mi ATMEL Corporation, at90ls8535-8mi Datasheet - Page 42

• Manufacturer Part Number: at90ls8535-8mi
• Description: 8-bit Microcontroller With 8k Bytes In-system Programmable Flash
• Manufacturer: ATMEL Corporation

8-bit Timer/Counter2
42
AT90S/LS8535
Table 16. PWM Outputs OCR1X = $0000 or TOP
Note:
In PWM mode, the Timer Overflow Flag1 (TOV1) is set when the counter advances from
$0000. Timer Overflow Interrupt1 operates exactly as in normal Timer/Counter mode,
i.e., it is executed when TOV1 is set, provided that Timer Overflow Interrupt1 and global
interrupts are enabled. This also applies to the Timer Output Compare1 flags and
interrupts.
Figure 34 shows the block diagram for Timer/Counter2.
Figure 34. Timer/Counter2 Block Diagram
The 8-bit Timer/Counter2 can select clock source from PCK2 or prescaled PCK2. It can
also be stopped as described in the specification for the Timer/Counter Control Register
(TCCR2).
The different status flags (Overflow and Compare Match) are found in the
Timer/Counter Interrupt Flag Register (TIFR). Control signals are found in the
COM1X1
X = A
1
1
1
7
7
7
TIMER/COUNTER2
8-BIT COMPARATOR
REGISTER2 (OCR2)
OUTPUT COMPARE
REGISTER (TIMSK)
TIMER INT. MASK
8-BIT DATA BUS
8-BIT ASYNCH T/C2 DATA BUS
(TCNT2)
COM1X0
PCK2
0
0
0
CK
0
1
1
T/C2 OVER-
FLOW IRQ
T/C CLEAR
T/C CLK SOURCE
UP/DOWN
REGISTER (TIFR)
TIMER INT. FLAG
SYNCH UNIT
T/C2 COMPARE
MATCH IRQ
OCR1X
$0000
TOP
TOP
CONTROL
LOGIC
REGISTER (TCCR2)
REGISTER (ASSR)
ASYNCH. STATUS
T/C2 CONTROL
Output OC1X
H
H
L
1041H–11/01
TOSC1
CK