M55800A Atmel Corporation, M55800A Datasheet - Page 27

• 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

11.3
11.4
1745F–ATARM–06-Sep-07
Data Bus Width
Byte-write or Byte-select Access
A data bus width of 8 or 16 bits can be selected for each chip select. This option is controlled by
the DBW field in the EBI_CSR (Chip-select Register) for the corresponding chip select.
Figure 11-2
Figure 11-2. Memory Connection for an 8-bit Data Bus
Figure 11-3
Figure 11-3. Memory Connection for a 16-bit Data Bus
Each chip select with a 16-bit data bus can operate with one of two different types of write
access:
This option is controlled by the BAT field in the EBI_CSR (Chip-select Register) for the corre-
sponding chip select.
Byte-write Access is used to connect 2 x 8-bit devices as a 16-bit memory page.
Figure 11-4
• Byte-write Access supports two Byte-write and a single read signal.
• Byte-select Access selects upper and/or lower byte with two byte-select lines, and separate
• The signal A0/NLB is not used.
• The signal NWR1/NUB is used as NWR1 and enables upper byte writes.
• The signal NWR0/NWE is used as NWR0 and enables lower byte writes.
• The signal NRD/NOE is used as NRD and enables half-word and byte reads.
read and write signals.
shows how to connect a 512K x 8-bit memory on NCS2.
shows how to connect a 512K x 16-bit memory on NCS2.
shows how to connect two 512K x 8-bit devices in parallel on NCS2.
EBI
EBI
D8 - D15
A1 - A19
D0 - D7
D8 - D15
A1 - A18
NCS2
D0 - D7
NWE
NOE
NWR1
NWR0
NUB
NLB
NCS2
NRD
A0
D0 - D7
D8 - D15
A0 - A18
Low Byte Enable
High Byte Enable
Write Enable
Output Enable
Memory Enable
D0 - D7
A1 - A18
A0
Write Enable
Output Enable
Memory Enable
AT91M5880A
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