AT91RM9200-CI-002 Atmel, AT91RM9200-CI-002 Datasheet - Page 165

• Manufacturer Part Number: AT91RM9200-CI-002
• Description: IC ARM9 MCU 256 BGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91RM9200-CI-002

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 180MHz
• Connectivity: EBI/EMI, Ethernet, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: POR
• Number Of I /o: 122
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: ROM
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-BGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

Figure 18-14. NWAIT Behavior in Read Access [NWS = 3]
Notes:
Figure 18-15. NWAIT Behavior in Write Access [NWS = 3]
18.6.4.3
1768I–ATARM–09-Jul-09
internally synchronized
internally synchronized
1. Early Read Protocol
2. Standard Read Protocol
Data Float Wait States
NWAIT
NWAIT
D[15:0]
A[22:0]
NWE
MCK
A[22:0]
NWAIT
NWAIT
MCK
NRD
NCS
Some memory devices are slow to release the external bus. For such devices, it is necessary to
add wait states (data float wait states) after a read access before starting a write access or a
read access to a different external memory.
The Data Float Output Time (t
field of the SMC_CSR register for the corresponding chip select
Wait Delay from NRD
(1)
Wait Delay
from NWE
(2)
Synchronization Delay
Synchronization Delay
NWAIT
NWAIT
DF
) for each external memory device is programmed in the TDF
(“SMC Chip Select Registers”
AT91RM9200
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