Phytec phyCORE-OMAP44 Series, Руководство по оборудованию

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phyCORE-OMAP44xx Part I: PCM-049/phyCORE-OMAP44xx System on Module
L-760e_1 © PHYTEC Messtechnik GmbH 2012 43
1.6 System Memory
The phyCORE-OMAP44xx provides three types of on-board memory:
1. LPDDR2 (PoP): 512 MB (up to 1 GB)
2. NAND Flash: 512 MB (up to 4 GB)
3. I
2
C-EEPROM: 32 kB
The following sections of this chapter detail each memory type used on the phyCORE-OMAP44xx.
1.6.1 LPDDR2-SDRAM (U1, PoP Memory)
The RAM memory of the phyCORE-OMAP44xx is comprised of a 64-bit wide LPDDR2-SDRAM PoP (Package on
Package) chip at U1 which is internal subdivided in two 32-bit wide LPDDR2-SDRAM dies. The chip is connected
to the special LPDRR2 interface called extended memory interface (EMIF) of the OMAP44xx processor.
The LPDDR2-SDRAM memory is accessed via the second AHB port starting at 0x8000 0000.
Typically the LPDDR2-SDRAM initialization is performed by a boot loader or operating system following a
power-on reset and must not be changed at a later point by any application code. When writing custom code
independently of an operating system or boot loader, SDRAM must be initialized by accessing the appropriate
SDRAM configuration registers on the OMAP44xx controller. Refer to the OMAP44xx Reference Manual for
accessing and configuring these registers.