Motorola CPCI-6115 - Manual (Page 82)

CPCI-6115 CompactPCI Single Board Computer Installation and Use (6806800A68D)
Functional Description Flash Memory
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4.3.6 Flash Memory
The CPCI-6115 contains two banks of flash memory accessed via the device controller bus
contained within the MV64360 chip. Bank B consists of two Intel StrataFlash +3.3 V devices,
configured to operate in 16-bit mode, to form a 32-bit flash bank. Bank B provides a minimum
of 8 MB of flash memory.
Bank A consists of two Intel StrataFlash +3.3 V devices, configured to operate in 16-bit mode,
to form a 32-bit flash bank. The following table defines the flash type and size options for Bank
A. The CPCI-6115 standard product is built with the 128 megabit devices. These Intel
StrataFlash devices support page read mode operations with a 8-byte page size per device.
Since the StrataFlash initial access time is 150ns, onboard hardware is used to guarantee initial
access timing using the Device port READY# signal.
A flash write protect header is provided on the CPCI-6115 to enable write protection of the
entire Bank A flash via the device VPEN pins when the jumper is not installed. Bank A write
protection can also be enabled by software using the System Register 2 FLASH_WP bit in the
MV64360 when the jumper is installed.
There is a boot bank select jumper on the CPCI-6115 that selects either Flash Bank A or Bank
B as the boot bank. This jumper effectively routes the MV64360 BOOTCS# pin to either Bank
A/Bank B and chip select CS0# to the other bank (Bank B/Bank A).
4.3.7 NVRAM, Real-Time Clock, Watchdog Timer
An SGS-Thompson M48T37V device is connected to the MV64360 device controller bus. This
device provides 32 KB of nonvolatile static RAM, a real-time clock and a watchdog function.
Refer to the M48T37V Data Sheet for programming information. The M48T37V consists of two
parts:
z One 44-pin 330mil SO device that contains the RTC, the oscillator, the power fail detection,
the watchdog timer logic, 32 KB of SRAM and gold-plated sockets for the SNAPHAT
battery.
z One SNAPHAT that houses the battery and the crystal.
The SNAPHAT package is mounted on top of the SO MT48T37V device after the completion
of the surface mount process.
The watchdog timer can generate a timeout period of 62.5 msec to 128 seconds. The output of
the watchdog timer can be programmed to generate an interrupt or reset the board if enabled.
Table 4-5 Bank A Flash Options
Flash Bank Size Intel Part Number Device Size
8 MB 28F320J3D 32 megabit
16 MB 28F640J3D 64 megabit
32 MB 28F128J3D 128 megabit
64 MB 28F256P3 256 megabit