AT90USB1286-16MU ATMEL [ATMEL Corporation], AT90USB1286-16MU Datasheet - Page 171

• Manufacturer Part Number: AT90USB1286-16MU
• Description: Microcontroller with 64/128K Bytes of ISP Flash and USB Controller
• Manufacturer: ATMEL [ATMEL Corporation]

16. Output Compare Modulator (OCM1C0A)
16.1
16.2
7593A–AVR–02/06
Overview
Description
The Output Compare Modulator (OCM) allows generation of waveforms modulated with a carrier
frequency. The modulator uses the outputs from the Output Compare Unit C of the 16-bit
Timer/Counter1 and the Output Compare Unit of the 8-bit Timer/Counter0. For more details
about these Timer/Counters see
calers” on page 99
150.
Figure 16-1. Output Compare Modulator, Block Diagram
When the modulator is enabled, the two output compare channels are modulated together as
shown in the block diagram
The Output Compare unit 1C and Output Compare unit 2 shares the PB7 port pin for output. The
outputs of the Output Compare units (OC1C and OC0A) overrides the normal PORTB7 Register
when one of them is enabled (i.e., when COMnx1:0 is not equal to zero). When both OC1C and
OC0A are enabled at the same time, the modulator is automatically enabled.
The functional equivalent schematic of the modulator is shown on
includes part of the Timer/Counter units and the port B pin 7 output driver circuit.
Figure 16-2. Output Compare Modulator, Schematic
( From Waveform Generator )
( From Waveform Generator )
COMA01
COMA00
COM1C1
COM1C0
Timer/Counter 1
Timer/Counter 0
and
PORTB7
D
D
D
OC1C
OC0A
“8-bit Timer/Counter2 with PWM and Asynchronous Operation” on page
Q
Q
Q
(Figure
“Timer/Counter0, Timer/Counter1, and Timer/Counter3 Pres-
DATABUS
16-1).
OC1C
OC0A
Modulator
0
1
DDRB7
D
AT90USB64/128
Q
1
0
Figure
OC0A / PB7
OC1C /
16-2. The schematic
Pin
Vcc
OC0A/ PB7
OC1C /
Pin
171