ATMEGA8515-16JU Atmel, ATMEGA8515-16JU Datasheet - Page 100
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ATMEGA8515-16JU
Manufacturer Part Number
ATMEGA8515-16JU
Description
IC MCU AVR 8K 16MHZ IND 44-PLCC
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA8515-16JU
Core Processor
AVR
Core Size
8-Bit
Speed
16MHz
Connectivity
EBI/EMI, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
35
Program Memory Size
8KB (4K x 16)
Program Memory Type
FLASH
Eeprom Size
512 x 8
Ram Size
512 x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-PLCC
Package
44PLCC
Device Core
AVR
Family Name
ATmega
Maximum Speed
16 MHz
Operating Supply Voltage
5 V
Data Bus Width
8 Bit
Number Of Programmable I/os
35
Interface Type
SPI/USART
Number Of Timers
2
Processor Series
ATMEGA8x
Core
AVR8
Data Ram Size
512 B
Maximum Clock Frequency
16 MHz
Maximum Operating Temperature
+ 85 C
Mounting Style
SMD/SMT
3rd Party Development Tools
EWAVR, EWAVR-BL
Development Tools By Supplier
ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
Minimum Operating Temperature
- 40 C
Cpu Family
ATmega
Device Core Size
8b
Frequency (max)
16MHz
Total Internal Ram Size
512Byte
# I/os (max)
35
Number Of Timers - General Purpose
2
Operating Supply Voltage (typ)
5V
Operating Supply Voltage (max)
5.5V
Operating Supply Voltage (min)
4.5V
Instruction Set Architecture
RISC
Operating Temp Range
-40C to 85C
Operating Temperature Classification
Industrial
Mounting
Surface Mount
Pin Count
44
Package Type
PLCC
For Use With
ATSTK600 - DEV KIT FOR AVR/AVR32770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRISP2 - PROGRAMMER AVR IN SYSTEMATSTK500 - PROGRAMMER AVR STARTER KIT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Data Converters
-
Lead Free Status / Rohs Status
Details
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Accessing 16-bit
Registers
100
ATmega8515(L)
The TCNT1, OCR1A/B, and ICR1 are 16-bit registers that can be accessed by the AVR
CPU via the 8-bit data bus. The 16-bit register must be byte accessed using two read or
write operations. Each 16-bit timer has a single 8-bit register for temporary storing of the
high byte of the 16-bit access. The same temporary register is shared between all 16-bit
registers within each 16-bit timer. Accessing the low byte triggers the 16-bit read or write
operation. When the low byte of a 16-bit register is written by the CPU, the high byte
stored in the temporary register, and the low byte written are both copied into the 16-bit
register in the same clock cycle. When the low byte of a 16-bit register is read by the
CPU, the high byte of the 16-bit register is copied into the temporary register in the
same clock cycle as the low byte is read.
Not all 16-bit accesses uses the temporary register for the high byte. Reading the
OCR1A/B 16-bit registers does not involve using the temporary register.
To do a 16-bit write, the high byte must be written before the low byte. For a 16-bit read,
the low byte must be read before the high byte.
The following code examples show how to access the 16-bit timer registers assuming
that no interrupts updates the temporary register. The same principle can be used
directly for accessing the OCR1A/B and ICR1 Registers. Note that when using “C”, the
compiler handles the 16-bit access.
Note:
The assembly code example returns the TCNT1 value in the r17:r16 register pair.
It is important to notice that accessing 16-bit registers are atomic operations. If an inter-
rupt occurs between the two instructions accessing the 16-bit register, and the interrupt
code updates the temporary register by accessing the same or any other of the 16-bit
timer registers, then the result of the access outside the interrupt will be corrupted.
Therefore, when both the main code and the interrupt code update the temporary regis-
ter, the main code must disable the interrupts during the 16-bit access.
Assembly Code Examples
C Code Examples
...
; Set TCNT1 to 0x01FF
ldi r17,0x01
ldi r16,0xFF
out TCNT1H,r17
out TCNT1L,r16
; Read TCNT1 into r17:r16
in r16,TCNT1L
in r17,TCNT1H
...
unsigned int i;
...
/* Set TCNT1 to 0x01FF */
TCNT1 = 0x1FF;
/* Read TCNT1 into i */
i = TCNT1;
...
1. See “About Code Examples” on page 7.
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