M55800A Atmel Corporation, M55800A Datasheet - Page 25

• Manufacturer Part Number: M55800A
• Manufacturer: Atmel Corporation

Specifications of M55800A

• Flash (kbytes): 0 Kbytes
• Pin Count: 176
• Max. Operating Frequency: 33 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 58
• Ext Interrupts: 58
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Uart: 3
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 72
• Resistive Touch Screen: No
• Dac Channels: 1
• Dac Resolution (bits): 10
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 8
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 3.3/5.0
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 6
• Output Compare Channels: 6
• Input Capture Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

11.1
1745F–ATARM–06-Sep-07
External Memory Mapping
The memory map associates the internal 32-bit address space with the external 24-bit address
bus.
The memory map is defined by programming the base address and page size of the external
memories (see EBI User Interface registers EBI_CSR0 to EBI_CSR7). Note that A0 - A23 is only
significant for 8-bit memory; A1 - A23 is used for 16-bit memory.
If the physical memory device is smaller than the programmed page size, it wraps around and
appears to be repeated within the page. The EBI correctly handles any valid access to the mem-
ory device within the page. (See
In the event of an access request to an address outside any programmed page, an Abort signal
is generated. Two types of Abort are possible: instruction prefetch abort and data abort. The cor-
responding exception vector addresses are respectively 0x0000 000C and 0x0000 0010. It is up
to the system programmer to program the error handling routine to use in case of an Abort (see
the ARM7TDMI datasheet for further information).
Figure 11-1. External Memory Smaller than Page Size
Memory
Map
1-Mbyte Device
1-Mbyte Device
1-Mbyte Device
1-Mbyte Device
Figure
11-1.)
Low
Low
Low
Low
Hi
Hi
Hi
Hi
Base + 4M Byte
Base + 3M Byte
Base + 2M Byte
Base + 1M Byte
Base
AT91M5880A
Repeat 3
Repeat 2
Repeat 1
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