ATmega168 Automotive Atmel Corporation, ATmega168 Automotive Datasheet - Page 269

• Manufacturer Part Number: ATmega168 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega168 Automotive

• Flash (kbytes): 16 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

24.6
7530I–AVR–02/10
Addressing the Flash During Self-Programming
• Bit 2 – PGWRT: Page Write
If this bit is written to one at the same time as SELFPRGEN, the next SPM instruction within four
clock cycles executes Page Write, with the data stored in the temporary buffer. The page
address is taken from the high part of the Z-pointer. The data in R1 and R0 are ignored. The
PGWRT bit will auto-clear upon completion of a Page Write, or if no SPM instruction is executed
within four clock cycles. The CPU is halted during the entire Page Write operation if the NRWW
section is addressed.
• Bit 1 – PGERS: Page Erase
If this bit is written to one at the same time as SELFPRGEN, the next SPM instruction within four
clock cycles executes Page Erase. The page address is taken from the high part of the
Z-pointer. The data in R1 and R0 are ignored. The PGERS bit will auto-clear upon completion of
a Page Erase, or if no SPM instruction is executed within four clock cycles. The CPU is halted
during the entire Page Write operation if the NRWW section is addressed.
• Bit 0 – SELFPRGEN: Self Programming Enable
This bit enables the SPM instruction for the next four clock cycles. If written to one together with
either RWWSRE, BLBSET, PGWRT or PGERS, the following SPM instruction will have a spe-
cial meaning, see description above. If only SELFPRGEN is written, the following SPM
instruction will store the value in R1:R0 in the temporary page buffer addressed by the Z-pointer.
The LSB of the Z-pointer is ignored. The SELFPRGEN bit will auto-clear upon completion of an
SPM instruction, or if no SPM instruction is executed within four clock cycles. During Page Erase
and Page Write, the SELFPRGEN bit remains high until the operation is completed.
Writing any other combination than “10001”, “01001”, “00101”, “00011” or “00001” in the lower
five bits will have no effect.
The Z-pointer is used to address the SPM commands.
Since the Flash is organized in pages (see
be treated as having two different sections. One section, consisting of the least significant bits, is
addressing the words within a page, while the most significant bits are addressing the pages.
This is1 shown in
addressed independently. Therefore it is of major importance that the Boot Loader software
addresses the same page in both the Page Erase and Page Write operation. Once a program-
ming operation is initiated, the address is latched and the Z-pointer can be used for other
operations.
The only SPM operation that does not use the Z-pointer is Setting the Boot Loader Lock bits.
The content of the Z-pointer is ignored and will have no effect on the operation. The LPM
instruction does also use the Z-pointer to store the address. Since this instruction addresses the
Flash byte-by-byte, also the LSB (bit Z0) of the Z-pointer is used.
Bit
ZH (R31)
ZL (R30)
Z15
15
Z7
7
Figure
Z14
Z6
14
6
24-3. Note that the Page Erase and Page Write operations are
Z13
13
Z5
5
ATmega48/88/168 Automotive
Table 25-12 on page
Z12
12
Z4
4
Z11
11
Z3
3
Z10
10
Z2
2
284), the Program Counter can
Z9
Z1
9
1
Z8
Z0
8
0
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