AT91SAM9261-CJ-999 Atmel, AT91SAM9261-CJ-999 Datasheet - Page 188

• 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: -

21.11.4
Figure 21-30. NWAIT Latency
6062M–ATARM–23-Mar-09
intenally synchronized
NWAIT signal
NBS0, NBS1,
NBS2, NBS3,
A0,A1
NWAIT Latency and Read/Write Timings
NWAIT
A
[25:2]
MCK
NRD
There may be a latency between the assertion of the read/write controlling signal and the asser-
tion of the NWAIT signal by the device. The programmed pulse length of the read/write
controlling signal must be at least equal to this latency plus the 2 cycles of resynchronization + 1
cycle. Otherwise, the SMC may enter the hold state of the access without detecting the NWAIT
signal assertion. This is true in frozen mode as well as in ready mode. This is illustrated on
ure
When EXNW_MODE is enabled (ready or frozen), the user must program a pulse length of the
read and write controlling signal of at least:
minimal pulse length = NWAIT latency + 2 resynchronization cycles + 1 cycle
21-30.
4
NWAIT latency
3
2 cycle resynchronization
minimal pulse length
2
EXNW_MODE = 10 or 11
READ_MODE = 1 (NRD_controlled)
NRD_PULSE = 5
Read cycle
1
AT91SAM9261 Preliminary
0
0
WAIT STATE
0
Fig-
188