On-Card Memory; Soldered Flash - Emerson Pm8560 User Manual

Octal e1/t1/j1 line interface ptmc

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Section 4

On-Card Memory

This chapter describes the various memory devices on the Pm8560. These include:

• 32 megabytes soldered flash memory

• 512 kilobytes socketed flash on the DMC

• 256 to 512 megabytes DDR SDRAM devices

• three serial EEPROMs

• MPC8560 configuration ROM

The SDRAM, EPROM and flash are supported by the MPC8560 memory controller, the main

component of the Local Bus Controller (LBC). The memory controller is responsible for con-

trolling eight memory banks shared by the following machines: synchronous DRAM, Gen-

eral-Purpose Chip-Select Machine (GPCM), and up to three User Programmable Machines

(UPM). See the MPC8560 chip selects in

Table 3-4

The Pm8560 uses the 16-bit flash, starting at physical address E000,0000

for the default

boot device. See page 10-7 for the DMC socketed boot device. This 128-megabit (16 mega-

byte) device is organized as one-hundred-twenty-eight 128-kilobyte erase blocks. Blocks

are selectively and individually lockable and unlockable in-system. A 128-bit protection reg-

ister has multiple uses, including unique flash device identification. Before programming or

erasing a block in flash, mask the internal reset sources for HRESET* so that the board does

not allow reset until flash is programmed or erased. See page 11-4 for updating the moni-

tor in soldered flash.

A block erase operation erases one of the device's 128-kilobyte clocks typically within one

second—independent of other blocks. Each block can be independently erased 100,000

times. Block erase suspend mode allows system software to suspend block erase to read or

program data from any other block. Similarly, program suspend allows system software to

suspend programming (byte/word program and write-to-buffer operations) to read data or

execute code from any other block that is not being suspended.

Each device incorporates a write buffer of 32 bytes (16 words) to allow optimum program-

ming performance. By using the write buffer, data is programmed in buffer increments. This

feature can improve system program performance more than twenty times over non-write

buffer writes.

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Pm8560 User's Manual

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