ATMEGA162-16PJ Atmel, ATMEGA162-16PJ Datasheet - Page 218

• Manufacturer Part Number: ATMEGA162-16PJ
• Description: IC MCU AVR 16K 5V 16MHZ 40-DIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA162-16PJ

• 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: 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
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Data Converters: -

RWW – Read-While-
Write Section
NRWW – No Read-
While-Write Section
218
ATmega162/V
If a Boot Loader software update is programming a page inside the RWW section, it is possible
to read code from the Flash, but only code that is located in the NRWW section. During an ongo-
ing programming, the software must ensure that the RWW section never is being read. If the
user software is trying to read code that is located inside the RWW section (i.e., by a
call/jmp/lpm or an interrupt) during programming, the software might end up in an unknown
state. To avoid this, the interrupts should either be disabled or moved to the Boot Loader sec-
tion. The Boot Loader section is always located in the NRWW section. The RWW Section Busy
bit (RWWSB) in the Store Program Memory Control Register (SPMCR) will be read as logical
one as long as the RWW section is blocked for reading. After a programming is completed, the
RWWSB must be cleared by software before reading code located in the RWW section.
“Store Program Memory Control Register – SPMCR” on page 221.
RWWSB.
The code located in the NRWW section can be read when the Boot Loader software is updating
a page in the RWW section. When the Boot Loader code updates the NRWW section, the CPU
is halted during the entire Page Erase or Page Write operation.
Table 88. Read-While-Write Features
Figure 93. Read-While-Write vs. No Read-While-Write
pointer Address During the
Which Section does the Z-
Programming?
NRWW section
RWW section
Z-pointer
Addresses RWW
Section
Code Located in
NRWW Section
Can be Read During
the Operation
Which Section Can be
Programming?
NRWW section
Read During
Read-While-Write
No Read-While-Write
(RWW) Section
(NRWW) Section
None
Is the CPU
Halted?
Yes
No
Z-pointer
Addresses NRWW
Section
CPU is Halted
During the Operation
for details on how to clear
Read-While-
Supported?
Write
Yes
No
2513K–AVR–07/09
See