AT91SAM9261-CJ-999 Atmel, AT91SAM9261-CJ-999 Datasheet - Page 698

• Manufacturer Part Number: AT91SAM9261-CJ-999
• Description: IC MCU ARM9 ULTRA LP 217LFBGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM9261-CJ-999

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 190MHz
• Connectivity: EBI/EMI, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: DMA, LCD, POR, PWM, WDT
• Number Of I /o: 96
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: ROM
• Ram Size: 192K x 8
• Voltage - Supply (vcc/vdd): 1.08 V ~ 1.32 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 217-LFBGA
• For Use With: AT91SAM9261-EK - KIT EVAL FOR AT91SAM926EJ-SAT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

42.2.8
42.2.8.1
698
AT91SAM9261 Preliminary
Reset Controller (RSTC)
RSTC: Reset During SDRAM Accesses
When a User Reset occurs during SDRAM read access, the SDRAM clock is turned off while
data are ready to be read on the data bus. The SDRAM maintains the data until the clock
restarts.
If the user Reset is programmed to assert a general reset, the data maintained by the SDRAM
leads to a data bus conflict and adversely affects the boot memories connected on the EBI:
In the interrupt routine, Power Down SDRAM properly and perform Peripheral and Processor
Reset with software in assembler.
Example with libV3.
• NAND Flash boot functionality, if the system boots out of internal ROM.
• NOR Flash boot, if the system boots on an external memory connected on the EBI CS0.
1. Avoid User Reset to generate a system reset.
2. Trap the User Reset with an interrupt.
• The main code:
• The C SYS handler:
Problem Fix/Workaround
//user reset interrupt setting
*AT91C_RSTC_RMR = (0xA5<<24) | (0x4<<8) | AT91C_RSTC_URSTIEN;
extern void soft_user_reset(void);
void sysc_handler(void){
//check if interrupt comes from RSTC
}
// Configure AIC controller to handle SSC interrupts
AT91F_AIC_ConfigureIt (
// Enable SYSC interrupt in AIC
AT91F_AIC_EnableIt(AT91C_BASE_AIC, AT91C_ID_SYS);
soft_user_reset();
//never reached
while(1);
if( (*AT91C_RSTC_RSR & AT91C_RSTC_URSTS ) == AT91C_RSTC_URSTS){
}
AT91C_BASE_AIC,
AT91C_ID_SYS,
AT91C_AIC_PRIOR_HIGHEST,
AT91C_AIC_SRCTYPE_INT_EDGE_TRIGGERED, // Level sensitive
sysc_handler );
// System peripheral ID
// AIC base address
// Max priority
6062M–ATARM–23-Mar-09