ATmega162 Atmel Corporation, ATmega162 Datasheet - Page 32

• Manufacturer Part Number: ATmega162
• Manufacturer: Atmel Corporation

Specifications of ATmega162

• Flash (kbytes): 16 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 35
• Ext Interrupts: 3
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• 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 85
• I/o Supply Class: 1.8 to 5.5
• Operating Voltage (vcc): 1.8 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 6
• Input Capture Channels: 2
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

Special Function IO
Register – SFIOR
Using all Locations of
External Memory
Smaller than 64 KB
32
ATmega162/V
• Bit 6 – XMBK: External Memory Bus Keeper Enable
Writing XMBK to one enables the Bus Keeper on the AD7:0 lines. When the Bus Keeper is
enabled, AD7:0 will keep the last driven value on the lines even if the XMEM interface has tri-
stated the lines. Writing XMBK to zero disables the Bus Keeper. XMBK is not qualified with SRE,
so even if the XMEM interface is disabled, the bus keepers are still activated as long as XMBK is
one.
• Bit 6..3 – XMM2, XMM1, XMM0: External Memory High Mask
When the External Memory is enabled, all Port C pins are used for the high address byte by
default. If the full 60KB address space is not required to access the external memory, some, or
all, Port C pins can be released for normal Port Pin function as described in
described in
XMMn bits to access all 64KB locations of the external memory.
Table 4. Port C Pins Released as Normal Port Pins when the External Memory is Enabled
Since the external memory is mapped after the internal memory as shown in
external memory is not addressed when addressing the first 1,280 bytes of data space. It may
appear that the first 1,280 bytes of the external memory are inaccessible (external memory
addresses 0x0000 to 0x04FF). However, when connecting an external memory smaller than 64
KB, for example 32 KB, these locations are easily accessed simply by addressing from address
0x8000 to 0x84FF. Since the External Memory Address bit A15 is not connected to the external
memory, addresses 0x8000 to 0x84FF will appear as addresses 0x0000 to 0x04FF for the exter-
nal memory. Addressing above address 0x84FF is not recommended, since this will address an
external memory location that is already accessed by another (lower) address. To the Applica-
tion software, the external 32 KB memory will appear as one linear 32 KB address space from
0x0500 to 0x84FF. This is illustrated in
ATmega161 compatibility mode, configuration A to the non-compatible mode.
Bit
Read/Write
Initial Value
XMM2
0
0
0
0
1
1
1
1
XMM1
0
0
1
1
0
0
1
1
“Using all 64KB Locations of External Memory” on page
TSM
R/W
7
0
XMM0
0
1
0
1
0
1
0
1
XMBK
R/W
6
0
# Bits for External Memory Address
8 (Full 60 KB space)
7
6
5
4
3
2
No Address high bits
XMM2
R/W
5
0
XMM1
R/W
4
0
Figure
XMM0
R/W
3
0
17. Memory configuration B refers to the
PUD
R/W
2
0
PSR2
R/W
0
1
Released Port Pins
None
PC7
PC7 - PC6
PC7 - PC5
PC7 - PC4
PC7 - PC3
PC7 - PC2
Full Port C
34, it is possible to use the
PSR310
R/W
0
0
SFIOR
Figure
2513K–AVR–07/09
Table
11, the
4. As