AT90PWM1 Atmel Corporation, AT90PWM1 Datasheet - Page 206

• Manufacturer Part Number: AT90PWM1
• Manufacturer: Atmel Corporation

Specifications of AT90PWM1

• Flash (kbytes): 8 Kbytes
• Pin Count: 24
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 19
• Ext Interrupts: 4
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 125
• Analog Comparators: 2
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 105
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 12
• Input Capture Channels: 1
• Pwm Channels: 7
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

21.1
21.2
21.2.1
21.2.2
21.3
206
Boot Loader Features
Application and Boot Loader Flash Sections
Read-While-Write and No Read-While-Write Flash Sections
AT90PWM1
Application Section
BLS – Boot Loader Section
program memory. The program code within the Boot Loader section has the capability to write
into the entire Flash, including the Boot Loader memory. The Boot Loader can thus even modify
itself, and it can also erase itself from the code if the feature is not needed anymore. The size of
the Boot Loader memory is configurable with fuses and the Boot Loader has two separate sets
of Boot Lock bits which can be set independently. This gives the user a unique flexibility to select
different levels of protection.
•
•
•
•
•
•
•
Note:
The Flash memory is organized in two main sections, the Application section and the Boot
Loader section (see
BOOTSZ Fuses as shown in
have different level of protection since they have different sets of Lock bits.
The Application section is the section of the Flash that is used for storing the application code.
The protection level for the Application section can be selected by the application Boot Lock bits
(Boot Lock bits 0), see
Loader code since the SPM instruction is disabled when executed from the Application section.
While the Application section is used for storing the application code, the The Boot Loader soft-
ware must be located in the BLS since the SPM instruction can initiate a programming when
executing from the BLS only. The SPM instruction can access the entire Flash, including the
BLS itself. The protection level for the Boot Loader section can be selected by the Boot Loader
Lock bits (Boot Lock bits 1), see
Whether the CPU supports Read-While-Write or if the CPU is halted during a Boot Loader soft-
ware update is dependent on which address that is being programmed. In addition to the two
sections that are configurable by the BOOTSZ Fuses as described above, the Flash is also
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
on page 218
•
•
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
Read-While-Write Self-Programming
Flexible Boot Memory Size
High Security (Separate Boot Lock Bits for a Flexible Protection)
Separate Fuse to Select Reset Vector
Optimized Page
Code Efficient Algorithm
Efficient Read-Modify-Write Support
When erasing or writing a page located inside the RWW section, the NRWW section can be
read during the operation.
When erasing or writing a page located inside the NRWW section, the CPU is halted during
the entire operation.
1. A page is a section in the Flash consisting of several bytes (see
during programming. The page organization does not affect normal operation.
and
(1)
Figure 21-2 on page
Size
Figure
Table 66 on page
21-2). The size of the different sections is configured by the
Table 70 on page 218
Table 67 on page
209. The main difference between the two sections is:
210. The Application section can never store any Boot
210.
and
Figure
21-2. These two sections can
Table 83 on page
4378C–AVR–09/08
225) used
Table 71