AT90PWM316-16SUR Atmel, AT90PWM316-16SUR Datasheet - Page 267

• Manufacturer Part Number: AT90PWM316-16SUR
• Description: MCU AVR 16K FLASH 16MHZ 32-SOIC
• Manufacturer: Atmel
• Series: AVR® 90PWM Lightingr

Specifications of AT90PWM316-16SUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 27
• Program Memory Size: 16KB (16K x 8)
• 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 11x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 32-SOIC (7.5mm Width)
• For Use With: ATSTK600-SOIC - STK600 SOCKET/ADAPTER FOR SOICATAVRMC200 - KIT EVAL FOR AT90PWM3 ASYNCATAVRFBKIT - KIT DEMO BALLAST FOR AT90PWM2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

24.3.1
24.3.2
7710E–AVR–08/10
RWW – Read-While-Write Section
NRWW – No Read-While-Write Section
divided into two fixed sections, the Read-While-Write (RWW) section and the No Read-While-
Write (NRWW) section. The limit between the RWW- and NRWW sections is given in
7 on page 278
Note that the user software can never read any code that is located inside the RWW section dur-
ing a Boot Loader software operation. The syntax “Read-While-Write section” refers to which
section that is being programmed (erased or written), not which section that actually is being
read during a Boot Loader software update.
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 on-
going 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 and Status Register (SPMCSR) will be read
as logical one as long as the RWW section is blocked for reading. After a programming is com-
pleted, the RWWSB must be cleared by software before reading code located in the RWW
section.
details on how to clear 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 24-1.
Address During the Programming?
• When erasing or writing a page located inside the RWW section, the NRWW section can be
• When erasing or writing a page located inside the NRWW section, the CPU is halted during
Which Section does the Z-pointer
read during the operation.
the entire operation.
See “Store Program Memory Control and Status Register – SPMCSR” on page 271.
NRWW Section
RWW Section
Read-While-Write Features
and
Figure 24-2 on page
Which Section Can
269. The main difference between the two sections is:
be Read During
Programming?
NRWW Section
None
AT90PWM216/316
Is the CPU
Halted?
Yes
No
Read-While-Write
Supported?
Yes
No
Table 24-
267
for