NS7520B-1-C36 Digi International, NS7520B-1-C36 Datasheet - Page 98

• Manufacturer Part Number: NS7520B-1-C36
• Description: IC ARM MICROPROCESSOR 177BGA
• Manufacturer: Digi International
• Series: NET+ARM®r

Specifications of NS7520B-1-C36

• 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

Pin configuration
Table 34: MEM module pin configuration by memory type
8 6
A b o u t t h e M E M m o d u l e
About the MEM module
MEM module hardware initialization
SRAM
DRAM-FP
DRAM-EDO
SDRAM
Mode
The MEM module monitors the BBus interface for access to the BUS module; that is,
any access not addressing internal resources. If the BBus for the access corresponds
to a Base Address register in the MEM module, the module provides the memory
access signals and responds to the BBus with the appropriate completion signal.
The MEM module can be configured to interface with FP, EDO, or synchronous DRAM
(SDRAM), although the NS7520 cannot interface with more than one device type at a
time.
Many NS7520 configuration features are application-specific and need to be
configured at powerup before the CPU boots. See "NS7520 bootstrap initialization" on
page 59.
PORTA2, the DRAM address multiplexer, provides for an external address mux for
SDRAM, FP DRAM, or EDO DRAM.
The NS7520 uses several pins to support SRAM and DRAM devices. The MEM module
controls the following signals: ADDR[27:0], CS[4:0], CAS[3:0], WE_ and OE_. Table 34
shows how MEM module pins are configured for different memory types.
Address
Address
Address
Address
A27:14
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
Address
Internal mux
Internal mux
Internal mux
A13:0
CS[4:0]_
RAS_
RAS_
CS[4:0]_
CSx
———
CAS3_
CAS3_
RAS_
CAS3_
———
CAS2_
CAS2_
CAS_
CAS2_
———
CAS1_
CAS1_
WE_
CAS1_
———
A10/AP
CAS0_
CAS0_
CAS0_
OE_
OE_
OE_
——
OE_
WE_
WE_
WE_
——
WE_