Nokia Mobile Phones NSE-5 Series Service Manual page 60

NSE–5
System Module
Memories
The MCU program code resides in an external program memory, size
is16Mbits. MCU work (data) memory size is 1Mbits. A special block in the
flash is used for storing the system and tuning parameters, user settings
and selections, a scratch pad and a short code memory.
A target is to eliminate the separate EEPROM memories and store the
non–volatile data into a dedicated block inside the flash memory in
products where the flash memory will not be replaced by an otp or a mask
prom for either technical or marketing reasons. Flash solution gives a cost
benefit in products where large EEPROM sizes are required. The used
flash memories are capable to perform erase and write operations with
the supplied 2.8V programming voltage.
The BusController (BUSC) section in the MAD2PR1 decodes the chip
select signals for the external memory devices and the system logic.
BUSC controls internal and external bus drivers and multiplexers
connected to the MCU data bus. The MCU address space is divided into
access areas with separate chip select signals. BUSC supports a
programmable number of wait states for each memory range.
Program Memory 32MBit Flash
The MCU program code resides in the flash program memory. The
program memory size is 32Mbits (2Mx16) . The default package is
uBGA48.
The flash memory has a power down pin that shall be kept low, during the
power up phase of the flash to ensure that the device is powered up in the
correct state, read only. The power down pin is utilized in the system sleep
mode by connecting the VCXOPwr to the flash power down pin to
minimize the flash power consumption during the sleep.
SRAM Memory
The work memory size is 2Mbits (256kx8) static ram in a shrinked
TSOP–32 package.Vcc is 2.8V and access time is 85 ns The work
memory is supplied from the common baseband VBB voltage and the
memory contents are lost when the baseband voltage is switched off. All
retainable data should be stored into the flash memory when the phone is
powered down.
EEPROM Emulated in FLASH Memory
An block in flash is used for a nonvolatile data memory to store the tuning
parameters and phone setup information. The short code memory for
storing user defined information is also implemented in the flash. The flash
size can vary between 2k to 8kbytes depending on the amount of short
code number locations supported. The memory is accessed through the
parallel bus.
Page 2 – 46
PAMS
Technical Documentation
Issue 1 07/99