at43usb320a ATMEL Corporation, at43usb320a Datasheet - Page 43

• Manufacturer Part Number: at43usb320a
• Description: Full-speed Usb Microcontroller With An Embedded Hub
• Manufacturer: ATMEL Corporation

1443E–USB–4/04
Timer/Counter1 Control Register A – TCCR1A
• Bits 7, 6 – COM1A1, COM1A0: Compare Output Mode1A, Bits 1 and 0
The COM1A1 and COM1A0 control bits determine any output pin action following a compare
match in Timer/Counter1. Any output pin actions affect pin OC1A (Output CompareA) pin 1.
This is an alternative function to an I/O port and the corresponding direction control bit must be
set (one) to control the output pin. The control configuration is shown in Table 13.
• Bits 5, 4 – COM1B1, COM1B0: Compare Output Mode1B, Bits 1 and 0
The COM1B1 and COM1B0 control bits determine any output pin action following a compare
match in Timer/Counter1. Any output pin actions affect pin OC1B (Output CompareB). The fol-
lowing control configuration is given:
Table 13. Compare 1 Mode Select
Notes:
• Bits 3..2 – Res: Reserved Bits
These bits are reserved bits in the AT43USB320A and always read zero.
• Bits 1..0 – PWM11, PWM10: Pulse Width Modulator Select Bits 1 and 0
These bits select PWM operation of Timer/Counter1 as specified in Table 14.
Table 14. PWM Mode Select
Initial Value
Read/Write
$2F ($4F)
COM1X1
Bit
PWM11
0
0
1
1
0
0
1
1
1. X = A or B
2. In PWM mode, these bits have a different function. Refer to Table 17 for a detailed
description.
COM1A1
R/W
7
0
COM1X0
PWM10
COM1A0
R/W
0
1
0
1
0
1
0
1
6
0
COM1B1
R/W
(2)
5
0
PWM operation of Timer/Counter1 is disabled.
Timer/Counter1 is an 8-bit PWM.
Timer/Counter1 is a 9-bit PWM.
Timer/Counter1 is a 10-bit PWM.
Description
Timer/Counter1 disconnected from output pin OC1X.
Toggle the OC1X output line.
Clear the OC1X output line (to zero).
Set the OC1X output line (to one).
Description
COM1B0
R/W
4
0
R
3
–
0
(1)
R
2
–
0
AT43USB320A
(1)
(1)
PWM11
R/W
1
0
PWM10
R/W
0
0
(1)
TCCR1A
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