AT90CAN128-16MJ Atmel, AT90CAN128-16MJ Datasheet - Page 34

• Manufacturer Part Number: AT90CAN128-16MJ
• Description: IC MCU AVR FLASH 128K 64-QFN
• Manufacturer: Atmel
• Series: AVR® 90CANr

Specifications of AT90CAN128-16MJ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: CAN, EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-VQFN Exposed Pad, 64-HVQFN, 64-SQFN, 64-DHVQFN
• For Use With: ATDVK90CAN1 - KIT DEV FOR AT90CAN128 MCU
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

4.5.8
34
AT90CAN32/64/128
Using all Locations of External Memory Smaller than 64 KB
Table 4-5.
Since the external memory is mapped after the internal memory as shown in
external memory is not addressed when addressing the first “ISRAM size” bytes of data space. It
may appear that the first “ISRAM size” bytes of the external memory are inaccessible (external
memory addresses 0x0000 to “ISRAM end”). However, when connecting an external memory
smaller than 64 KB, for example 32 KB, these locations are easily accessed simply by address-
ing from address 0x8000 to “ISRAM end + 0x8000”. Since the External Memory Address bit A15
is not connected to the external memory, addresses 0x8000 to “ISRAM end + 0x8000” will
appear as addresses 0x0000 to “ISRAM end” for the external memory. Addressing above
address “ISRAM end + 0x8000” is not recommended, since this will address an external mem-
ory location that is already accessed by another (lower) address. To the Application software,
the external 32 KB memory will appear as one linear 32 KB address space from “XMem start” to
“XMem start + 0x8000”. This is illustrated in
Figure 4-10. Address Map with 32 KB External Memory
XMM2
0
0
0
0
1
1
1
1
XMM1
0
0
1
1
0
0
1
1
ISRAM end + 0x8000
XMem start + 0x8000
Port C Pins Released as Normal Port Pins when the External Memory is Enabled
XMM0
ISRAM end
XMem start
0
1
0
1
0
1
0
1
0x7FFF
0xFFFF
0x0000
0x8000
# Bits for External Memory Address
8 (Full External Memory Space)
7
6
5
4
3
2
No Address high bits
AVR Memory Map
External Memory
Internal Memory
(Unused)
Figure
4-10.
External 32K SRAM
None
Released Port Pins
PC7
PC7 .. PC6
PC7 .. PC5
PC7 .. PC4
PC7 .. PC3
PC7 .. PC2
Full Port C
(Size=0x8000)
0x0000
ISRAM end
XMem start
0x7FFF
Figure
7679H–CAN–08/08
4-4, the