User Guide

PAMS Technical Documentation System Module & UI
NHM-8NX
Issue 1 05/02 ãNokia Corporation Page 43
address during the first cycle in the read/write access. Data access to the flash is per-
formed as a 16-bit access (MEMADDA[15:0]) in order to improve the data rate on the
bus.
The memory interface supports asynchronous read, burst mode synchronous read and
simultaneous read-while-write/erase, all controlled by the UPP.
Note: MEMADDA[23:22] is not used in this design.
Memory Description
The 64-Mbit density flash with 16 bit data access operates in both asynchronous random
access and synchronous burst access (with crossing partition boundaries) and has various
data protection features. Upon power up or reset, the device defaults to asynchronous
read configuration. Synchronous burst read is indicated to the device by writing to the
flash configuration register and can be terminated by deactivating the device.
The device supports reads and in-system erase and program operations at Vcc=1.8 V
(Voltage range 1.7-1.9 V). Flashing at production is supported at Vpp=12 V (for limited
exposure length only).
The NHM-8NX project has two flash suppliers, Intel and AMD. Device operations are sim-
ilar for both suppliers, with some differences as described in the following sections.
Depending on volume requirements and supplier capabilities, it is also possible that ST
will be a third supplier.
Flash Architecture
Intel
The device has 16, 4-Mbit partitions. There is one parameter partition and several main
partitions. The 4-Mbit parameter partition contains 8, 4K-word parameter blocks plus 7,
32-Kword main blocks. Each 4-Mbit main partition contains 8, 32-Kword blocks. The Top
partition is located at the highest physical device address and contains the parameter
partition. Each 4-Mbit partition has burst-read, write, and erase capabilities and the
device division into multiple partitions allows simultaneous read-while-write or read-
while erase operations in different partitions. Burst reads are allowed to cross partition
boundaries.
Besides the normal fast flashing using 12V as Vpp, the Intel flash supports a high-speed
programming mode (Enhanced Factory Programming, EFP) which is only for production
programming, not for after sales or re-programming purpose.
AMD
The AMD device consists of 2 partitions. Partition A contains 8, 8-Kbyte parameter blocks
plus 31, 64-Kbyte main blocks. Partition B contains 96, 64Kbyte main blocks. Partition A
is to replace an EEPROM and store non-volatile data. The flash can read from partition B