SAM7SE256 Atmel Corporation, SAM7SE256 Datasheet - Page 165

• Manufacturer Part Number: SAM7SE256
• Manufacturer: Atmel Corporation

Specifications of SAM7SE256

• Flash (kbytes): 256 Kbytes
• Pin Count: 144
• Max. Operating Frequency: 48 MHz
• Cpu: ARM7TDMI
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 88
• Ext Interrupts: 88
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 1
• Twi (i2c): 1
• Uart: 3
• Ssc: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 384
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 32
• Self Program Memory: NO
• External Bus Interface: 1
• Dram Memory: sdram
• Nand Interface: Yes
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 1.8/3.3
• Operating Voltage (vcc): 3.0 to 3.6
• Fpu: No
• Mpu / Mmu: Yes / No
• Timers: 3
• Output Compare Channels: 3
• Input Capture Channels: 3
• Pwm Channels: 4
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: No

22.6.2
22.6.2.1
22.6.2.2
6222F–ATARM–14-Jan-11
Write Access
Write Access Type
Byte Write Access
Figure 22-5. Memory Connection for a 16-bit Data Path Device
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 SMC_CSR for the corresponding chip select.
See
Byte Write Access is used to connect 2 x 8-bit devices as a 16-bit memory page.
Figure 22-6
• 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 enables half-word and byte reads.
read and write signals.
“SMC Chip Select Registers” on page
shows how to connect two 512K x 8-bit devices in parallel on NCS2 (BAT = 0)
SMC
D[15:8]
A[22:1]
D[7:0]
NCS2
NWE
NRD
NUB
NLB
196.
SAM7SE512/256/32
D[7:0]
D[15:8]
A[22:0]
Low Byte Enable
High Byte Enable
Write Enable
Output Enable
Memory Enable
165