AT91M55800-33CI Atmel, AT91M55800-33CI Datasheet - Page 15

• Manufacturer Part Number: AT91M55800-33CI
• Description: IC ARM7 MCU 176 BGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91M55800-33CI

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 33MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: POR, WDT
• Number Of I /o: 58
• Program Memory Type: ROMless
• Ram Size: 8K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 176-LFBGA
• For Use With: AT91EB55 - KIT EVAL FOR ARM AT91M55800A
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Other names: AT91M5580033CI

Abort Control
External Bus Interface
1745CS–ATARM–05/02
The abort signal providing a Data Abort or a Prefetch Abort exception to the ARM7TDMI
is asserted when accessing an undefined address in the EBI address space.
No abort is generated when reading the internal memory or by accessing the internal
peripherals, whether the address is defined or not.
The External Bus Interface handles the accesses between addresses 0x0040 0000 and
0xFFC0 0000. It generates the signals that control access to the external devices, and
can configure up to eight 16-Mbyte banks. In all cases it supports byte, half-word and
word aligned accesses.
For each of these banks, the user can program:
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The External Bus Interface features also the Early Read Protocol, configurable for all the
devices, that significantly reduces access time requirements on an external device.
Number of wait states
Number of data float times (wait time after the access is finished to prevent any bus
contention in case the device is too long in releasing the bus)
Data bus width (8-bit or 16-bit)
With a 16-bit wide data bus, the user can program the EBI to control one 16-bit
device (Byte Access Select Mode) or two 8-bit devices in parallel that emulate a 16-
bit memory (Byte-write Access mode).
AT91M55800A
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