AT91R40807-33AI Atmel, AT91R40807-33AI Datasheet - Page 25

• Manufacturer Part Number: AT91R40807-33AI
• Description: IC ARM7 MCU 176 TQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91R40807-33AI

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 33MHz
• Connectivity: EBI/EMI, UART/USART
• Peripherals: WDT
• Number Of I /o: 32
• Program Memory Type: ROMless
• Ram Size: 136K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -

1354D–ATARM–08/02
Byte Select Access is used to connect 16-bit devices in a memory page.
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Figure 12 shows how to connect a 16-bit device with byte and half-word access (e.g. 16-
bit SRAM) on NCS2.
Figure 12. Connection for a 16-bit Data Bus with Byte and Half-word Access
Figure 13 shows how to connect a 16-bit device without byte access (e.g. Flash) on
NCS2.
Figure 13. Connection for a 16-bit Data Bus without Byte Write Capability.
The signal A0/NLB is used as NLB and enables the lower byte for both read and
write operations.
The signal NWR1/NUB is used as NUB and enables the upper byte for both read
and write operations.
The signal NWR0/NWE is used as NWE and enables writing for byte or half word.
The signal NRD/NOE is used as NOE and enables reading for byte or half word.
EBI
EBI
D8 - D15
A1 - A19
D8 - D15
A1 - A19
D0 - D7
D0 - D7
NCS2
NWE
NCS2
NOE
NUB
NLB
NWE
NOE
NUB
NLB
D0 - D7
D8 - D15
A0 - A18
Write Enable
Output Enable
Memory Enable
D0 - D7
D8 - D15
A0 - A18
Low Byte Enable
High Byte Enable
Write Enable
Output Enable
Memory Enable
AT91X40 Series
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