AT91SAM7SE512-AU Atmel, AT91SAM7SE512-AU Datasheet - Page 212

• Manufacturer Part Number: AT91SAM7SE512-AU
• Description: IC ARM7 MCU FLASH 512K 128-LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7SE512-AU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: EBI/EMI, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 88
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 128-LQFP
• Cpu Family: 91S
• Device Core: ARM7TDMI
• Device Core Size: 32b
• Frequency (max): 55MHz
• Interface Type: EBI/SPI/TWI/USART
• Total Internal Ram Size: 32KB
• # I/os (max): 88
• Number Of Timers - General Purpose: 3
• Operating Supply Voltage (typ): 1.8/3.3V
• Operating Supply Voltage (max): 1.95/3.6V
• Operating Supply Voltage (min): 1.65/3V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 128
• Package Type: LQFP
• No. Of I/o's: 88
• Ram Memory Size: 32KB
• Cpu Speed: 48MHz
• No. Of Timers: 3
• No. Of Pwm Channels: 4
• Digital Ic Case Style: LQFP
• Rohs Compliant: Yes
• Processor Series: AT91SAMx
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 32 KB
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 1.8 V to 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, KSK-AT91SAM7S-PL, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM7SE-EK
• Minimum Operating Temperature: - 40 C
• For Use With: AT91SAM7SE-EK - EVAL BOARD FOR AT91SAM7SEAT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Compliant

23.7.2
Name:
Access:
Reset Value:
• COUNT: SDRAMC Refresh Timer Count
This 12-bit field is loaded into a timer that generates the refresh pulse. Each time the refresh pulse is generated, a refresh
burst is initiated. The value to be loaded depends on the SDRAMC clock frequency (MCK: Master Clock), the refresh rate
of the SDRAM device and the refresh burst length where 15.6 µs per row is a typical value for a burst of length one.
To refresh the SDRAM device even if the reset value is not equal to 0, this 12-bit field must be written. If this condition is not
satisfied, no refresh command is issued and no refresh of the SDRAM device is carried out.
212
31
23
15
–
–
–
7
SAM7SE512/256/32 Preliminary
SDRAMC Refresh Timer Register
30
22
14
SDRAMC_TR
Read/Write
0x00000800
–
–
–
6
29
21
13
–
–
–
5
28
20
12
–
–
–
4
COUNT
27
19
11
–
–
3
26
18
10
–
–
2
COUNT
25
17
–
–
9
1
6222F–ATARM–14-Jan-11
24
16
–
–
8
0