ATMEGA8515-16JU Atmel, ATMEGA8515-16JU Datasheet - Page 149
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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
Asynchronous Clock
Recovery
Asynchronous Data Recovery
2512K–AVR–01/10
The clock recovery logic synchronizes internal clock to the incoming serial frames. Fig-
ure 68 illustrates the sampling process of the start bit of an incoming frame. The sample
rate is 16 times the baud rate for Normal mode, and eight times the baud rate for Double
Speed mode. The horizontal arrows illustrate the synchronization variation due to the
sampling process. Note the larger time variation when using the Double Speed mode
(U2X = 1) of operation. Samples denoted zero are samples done when the RxD line is
idle (i.e., no communication activity).
Figure 68. Start Bit Sampling
When the clock recovery logic detects a high (idle) to low (start) transition on the RxD
line, the start bit detection sequence is initiated. Let sample 1 denote the first zero-sam-
ple as shown in the figure. The clock recovery logic then uses samples 8, 9, and 10 for
Normal mode, and samples 4, 5, and 6 for Double Speed mode (indicated with sample
numbers inside boxes on the figure), to decide if a valid start bit is received. If two or
more of these three samples have logical high levels (the majority wins), the start bit is
rejected as a noise spike and the Receiver starts looking for the next high to low-transi-
tion. If however, a valid start bit is detected, the clock recovery logic is synchronized and
the data recovery can begin. The synchronization process is repeated for each start bit.
When the Receiver clock is synchronized to the start bit, the data recovery can begin.
The data recovery unit uses a state machine that has 16 states for each bit in normal
mode and eight states for each bit in Double Speed mode. Figure 69 shows the sam-
pling of the data bits and the parity bit. Each of the samples is given a number that is
equal to the state of the recovery unit.
Figure 69. Sampling of Data and Parity Bit
The decision of the logic level of the received bit is taken by doing a majority voting of
the logic value to the three samples in the center of the received bit. The center samples
are emphasized on the figure by having the sample number inside boxes. The majority
voting process is done as follows: If two or all three samples have high levels, the
received bit is registered to be a logic 1. If two or all three samples have low levels, the
received bit is registered to be a logic 0. This majority voting process acts as a low pass
filter for the incoming signal on the RxD pin. The recovery process is then repeated until
a complete frame is received. Including the first stop bit. Note that the Receiver only
uses the first stop bit of a frame.
(U2X = 0)
(U2X = 1)
(U2X = 0)
(U2X = 1)
Sample
Sample
Sample
Sample
RxD
RxD
0
0
IDLE
0
1
1
1
1
2
2
3
2
3
2
4
4
5
3
5
3
6
6
7
4
7
4
8
8
START
BIT n
9
5
9
5
10
10
11
11
6
6
ATmega8515(L)
12
12
13
13
7
7
14
14
15
15
8
8
16
16
1
1
1
1
2
BIT 0
149
3
2