ATMEGA16A-AUR Atmel, ATMEGA16A-AUR Datasheet - Page 226

• Manufacturer Part Number: ATMEGA16A-AUR
• Description: MCU AVR 16KB FLASH 16MHZ 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA16A-AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

23. JTAG Interface and On-chip Debug System
23.1
23.2
23.3
226
Features
Overview
TAP – Test Access Port
ATmega16A
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The AVR IEEE std. 1149.1 compliant JTAG interface can be used for
A brief description is given in the following sections. Detailed descriptions for Programming via
the JTAG interface, and using the Boundary-scan Chain can be found in the sections
ming via the JTAG Interface” on page 280
232, respectively. The On-chip Debug support is considered being private JTAG instructions,
and distributed within ATMEL and to selected third party vendors only.
Figure 23-1
TAP Controller is a state machine controlled by the TCK and TMS signals. The TAP Controller
selects either the JTAG Instruction Register or one of several Data Registers as the scan chain
(Shift Register) between the TDI input and TDO output. The Instruction Register holds JTAG
instructions controlling the behavior of a Data Register.
The ID-Register, Bypass Register, and the Boundary-scan Chain are the Data Registers used
for board-level testing. The JTAG Programming Interface (actually consisting of several physical
and virtual Data Registers) is used for JTAG Serial Programming via the JTAG interface. The
Internal Scan Chain and Break Point Scan Chain are used for On-chip Debugging only.
The JTAG interface is accessed through four of the AVR’s pins. In JTAG terminology, these pins
constitute the Test Access Port – TAP. These pins are:
• Testing PCBs by using the JTAG Boundary-scan capability
• Programming the non-volatile memories, Fuses and Lock bits
• On-chip Debugging
JTAG (IEEE std. 1149.1 Compliant) Interface
Boundary-scan Capabilities According to the IEEE std. 1149.1 (JTAG) Standard
Debugger Access to:
Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface
On-chip Debugging Supported by AVR Studio
– All Internal Peripheral Units
– Internal and External RAM
– The Internal Register File
– Program Counter
– EEPROM and Flash Memories
– Extensive On-chip Debug Support for Break Conditions, Including
– AVR Break Instruction
– Break on Change of Program Memory Flow
– Single Step Break
– Program Memory Breakpoints on Single Address or Address Range
– Data Memory Breakpoints on Single Address or Address Range
shows a block diagram of the JTAG interface and the On-chip Debug system. The
and
®
“IEEE 1149.1 (JTAG) Boundary-scan” on page
8154B–AVR–07/09
“Program-