LG KS20 - External Memory Interface

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3. TECHNICAL BRIEF
LGE Internal Use Only Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.10. External memory interface
A. MSM7200
The MSM7200 device was designed to provide two distinct memory interfaces. EBI1 was targeted for
supporting DDR synchronous memory devices. EBI2 was targeted towards supporting slower
asynchronous devices such as LCD, NAND flash, SRAM, NOR flash etc. To support the high-
bandwidth, high-density, and low-latency requirements of the advanced on-chip applications, the
MSM7200 IC has two high-speed, high-performance memory slave interfaces: the external bus
interface 1 (EBI1) and the stack memory interface (SMI). To achieve higher bandwidth and better use
of the memory device interface, the SMI accepts multiple commands for the external memory device.
The SMI interface acts as a slave device to all of the bus masters within the MSM device. The masters
arbitrate to gain access to the SMI, and upon obtaining the access, they issue commands to the SMI.
The bus masters are connected to the SMI through an advanced extensible interface (AXI) bus bridge
(or global interconnect block) and communicate over a 64-bit, non-blocking AXI bus protocol. The AXI
bus bridge provides the arbitration logic for all of the bus masters.
• EBI1 Features
- Support for only low-power memories at 1.8-V I/O power supply voltage
- AXI bus frequencies up to 133 MHz
- A 16-bit/32-bit static and dynamic memory interface
• DDR SDRAM interface features include:
- Supports both 32-bit DDR SDRAM devices, up to 133-MHz bus speed
- Supports auto precharge and manual precharge
- Supports partial refresh
- Separate CKE pin per chip-select to support partial operation mode
- Idle powerdown to save idling power consumption
• EBI2 Features
- Support for asynchronous FLASH and SRAM(16bit & 8bit).
- Interface support for byte addressable 16bit devices(UB_N & LB_N signals).
- 2Mbytes of memory per chip select.
- Support for 8 bit/16bit wide NAND flash.
- Support for parallel LCD interfaces, port mapped of memory mapped(8 or 16 bit)
• Multi Chip Package : DDR SDRAM and NAND Flash merged 1 package
• 2Gb NAND(8bit) flash memory + 1Gb DDR SDRAM (32bit)
Interface Spec
Device Part Name Maker Read Access Time Write Access Time
NAND SS 45 ns 200 us
SDRAM 7.5 ns 7.5 ns
[Table 1.4] External memory interface for KS20
KAL009001M-D1YY SS