NS7520B-1-I46 Digi International, NS7520B-1-I46 Datasheet - Page 124

• Manufacturer Part Number: NS7520B-1-I46
• Description: IC ARM MICROPROCESSOR 177BGA
• Manufacturer: Digi International
• Series: NET+ARM®r

Specifications of NS7520B-1-I46

• Applications: Network Processor
• Core Processor: ARM7
• Program Memory Type: External Program Memory
• Controller Series: -
• Ram Size: External
• Interface: EBI/EMI, Ethernet, DMA, SPI, UART
• Number Of I /o: 16
• Voltage - Supply: 1.4 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 177-LFBGA
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

NS7520 SDRAM interconnect
Table 42: x32 SDRAM interconnect
1 1 2
S D R A M
CS/RAS_
CAS3_
CAS2_
CAS1_
CAS0_A10/AP
BE3_
BE2_
BE1_
BE0_
NS7520 signal
The NS7520 can interconnect to standard 16Mb and 64Mb SDRAM components, using
x32, x16, and x8 SDRAM configuration.
You can use 128Mb components in the x32 configuration, but not in the x8 or x16
configurations. The NS7520 SDRAM controller does not support SDRAM with more than
8 CAS (column addressing).
x32 SDRAM configuration
Table 42 shows the interconnect between the NS7520 and SDRAM when SDRAM is used
in an x32 configuration. This table shows two ways of constructing an x32 SDRAM
configuration:
In the 2Mx32 SDRAM configuration, bank selects BA0 and BA1 are not connected in
numerical order. The order is reversed so BA0 can be the same for the 4Mx32
configuration, and only BA1 needs to be swapped to upgrade.
Using two x16 SDARM components (referred to as Device 1 and Device 2)
Using one x32 SDRAM component
CS[4:0]_
RAS_
CAS_
WE_
A10/AP
UDQM_ - Device 1
LDQM_ - Device 1
UDQM_ - Device 2
LDQM_ - Device 2
2x16M SDRAM signal components
16 Mb (1Mx16)
N S 7 5 2 0 H a r d w a r e R e f e r e n c e , R e v G 9 / 2 0 0 7
CS[4:0]_
RAS_
CAS_
WE_
UDQM_ - Device 1
UDQM_ - Device 2
A10/AP
LDQM_ - Device 1
LDQM_ - Device 2
64Mb (4Mx16)
CS[4:0]_
RAS_
CAS_
WE_
A10/AP
DQM3
DQM2
DQM1
DQM0
1x32 SDRAM component
64Mb (2Mx32)
CS[4:0]_
RAS_
CAS_
WE_
A10/AP
DQM3
DQM2
DQM1
DQM0
128Mb (4Mx32)