SAM7SE256 Atmel Corporation, SAM7SE256 Datasheet - Page 166

• 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

22.6.2.3
166
SAM7SE512/256/32
Byte Select Access
Figure 22-6. Memory Connection for 2 x 8-bit Data Path Devices
Byte Select Access is used to connect 16-bit devices in a memory page.
Figure 22-7
device type) on NCS2 (BAT = 1).
Figure 22-7. Connection to a 16-bit Data Path Device with Byte and Half-word Access
• The signal A0/NLB is used as NLB and enables the lower byte for both read and write
• The signal NWR1/NUB is used as NUB and enables the upper byte for both read and write
• The signal NWR0/NWE is used as NWE and enables writing for byte or half-word.
• The signal NRD enables reading for byte or half-word.
operations.
operations.
shows how to connect a 16-bit device with byte and half-word access (e.g., SRAM
SMC
SMC
D[15:8]
A[22:1]
D[15:8]
A[19:1]
NWR1
NWR0
D[7:0]
NCS2
D[7:0]
NCS2
NWE
NRD
NRD
NUB
NLB
A0
D[15:8]
D[7:0]
A[18:0]
Write Enable
Read Enable
Memory Enable
A[18:0]
Write Enable
Read Enable
Memory Enable
D[15:8]
A[18:0]
Low Byte Enable
High Byte Enable
Write Enable
Output Enable
Memory Enable
D[7:0]
6222F–ATARM–14-Jan-11