ATMEGA169 ATMEL [ATMEL Corporation], ATMEGA169 Datasheet - Page 138
ATMEGA169
Manufacturer Part Number
ATMEGA169
Description
8-bit Microcontroller with 16K Bytes In-System Programmable Flash
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
1.ATMEGA169.pdf
(365 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
ATMEGA169P-15AT
Manufacturer:
PANASONIC
Quantity:
301
Part Number:
ATMEGA169P-15AT
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Part Number:
ATMEGA169P-16AU
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Company:
Part Number:
ATMEGA169PA-MU
Manufacturer:
ATMEL
Quantity:
31
Company:
Part Number:
ATMEGA169PAAU
Manufacturer:
INF
Quantity:
4 275
- Current page: 138 of 365
- Download datasheet (4Mb)
Asynchronous operation
of the Timer/Counter
Asynchronous Status
Register – ASSR
138
ATmega169/V
• Bit 4 – EXCLK: Enable External Clock Input
When EXCLK is written to one, and asynchronous clock is selected, the external clock
input buffer is enabled and an external clock can be input on Timer Oscillator 1 (TOSC1)
pin instead of a 32 kHz crystal. Writing to EXCLK should be done before asynchronous
operation is selected. Note that the crystal Oscillator will only run when this bit is zero.
• Bit 3 – AS2: Asynchronous Timer/Counter2
When AS2 is written to zero, Timer/Counter2 is clocked from the I/O clock, clk
AS2 is written to one, Timer/Counter2 is clocked from a crystal Oscillator connected to
the Timer Oscillator 1 (TOSC1) pin. When the value of AS2 is changed, the contents of
TCNT2, OCR2A, and TCCR2A might be corrupted.
• Bit 2 – TCN2UB: Timer/Counter2 Update Busy
When Timer/Counter2 operates asynchronously and TCNT2 is written, this bit becomes
set. When TCNT2 has been updated from the temporary storage register, this bit is
cleared by hardware. A logical zero in this bit indicates that TCNT2 is ready to be
updated with a new value.
• Bit 1 – OCR2UB: Output Compare Register2 Update Busy
When Timer/Counter2 operates asynchronously and OCR2A is written, this bit becomes
set. When OCR2A has been updated from the temporary storage register, this bit is
cleared by hardware. A logical zero in this bit indicates that OCR2A is ready to be
updated with a new value.
• Bit 0 – TCR2UB: Timer/Counter Control Register2 Update Busy
When Timer/Counter2 operates asynchronously and TCCR2A is written, this bit
becomes set. When TCCR2A has been updated from the temporary storage register,
this bit is cleared by hardware. A logical zero in this bit indicates that TCCR2A is ready
to be updated with a new value.
If a write is performed to any of the three Timer/Counter2 Registers while its update
busy flag is set, the updated value might get corrupted and cause an unintentional inter-
rupt to occur.
The mechanisms for reading TCNT2, OCR2A, and TCCR2A are different. When read-
ing TCNT2, the actual timer value is read. When reading OCR2A or TCCR2A, the value
in the temporary storage register is read.
Bit
Read/Write
Initial Value
R
7
–
0
R
6
–
0
R
5
–
0
EXCLK
R/W
4
0
AS2
R/W
3
0
TCN2UB
R
2
0
OCR2UB
R
1
0
TCR2UB
R
0
0
2514P–AVR–07/06
I/O
. When
ASSR
Related parts for ATMEGA169
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Atmel CryptoMemory
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
Atmel CryptoMemory
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
Atmel CryptoMemory, 16Kbit
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontrollers
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontroller with 16/32/64/128K Bytes In-System Programmable Flash
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
8-bit Atmel Microcontroller with 16/32/64K Bytes In-System Programmable Programmable
Manufacturer:
ATMEL [ATMEL Corporation]
Datasheet:
Part Number:
Description:
INTERVAL AND WIPE/WASH WIPER CONTROL IC WITH DELAY
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Low-Voltage Voice-Switched IC for Hands-Free Operation
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
MONOLITHIC INTEGRATED FEATUREPHONE CIRCUIT
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
AM-FM Receiver IC U4255BM-M
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Monolithic Integrated Feature Phone Circuit
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Multistandard Video-IF and Quasi Parallel Sound Processing
Manufacturer:
ATMEL Corporation
Datasheet: