Nokia RH-9 Series Ccs Technical Documentation page 55

CCS Technical Documentation
WE# and RST# must be high. During asynchronous read mode, the read cycle is initiated
by first applying the address to MEMADDA[15:0]. AVD#-low opens the internal address
latches and the address is latched at the rising edge of AVD#. OE#-low activates the
output and places selected data on MEMADDA [15:0].
In synchronous mode, the address is latched either at the rising edge of AVD# or at the
rising edge of the CLK while AVD#-low, whichever occurs first. OE# low activates the
output and places selected data on MEMADDA [15:0]. The bus controller will activate the
WAIT signal as required to meet the memory random access time.
Synchronous burst mode improves the data transfer between the memory and the sys-
tem processor. Synchronous read allows for outputs of four, eight or continuous words,
as well as reads that cross partition boundaries. The CLK input increments an internal
burst address generator, uses the WAIT signal to synchronize the flash with the MCU in
the UPP and outputs data every clock cycle. Burst access may be initiated from any
address location except for the 8 parameter blocks.
The flash also supports other read modes: Read identifier, read query and read status reg-
ister which execute as single-synchronous or asynchronous read cycles. WAIT is inactive
during these reads.
Write
The write cycle requires WE# -low and OE# -high. All write operations are asynchronous.
The write cycle is initiated by first applying the address to the multiplexed address/data
bus and the address lines A21-A16. The address and data are latched on the rising edge
of the WE# signal.
Simultaneous Operation
Intel
The Intel device allows simultaneous read-while-write or read-while erase operations in
different partitions. The Program/Erase Suspend command halts in-progress erase or pro-
gram operations. The Suspend command allows data to be accessed from blocks other
than the one being erased or programmed. An erase suspend allows system software to
pause an erase so it can read or program data in another block, and a program suspend
allows system software to pause programming so it can read (no erase possible) from
other locations within that partition.
AMD
The device can perform simultaneous read-while-write or read-while-erase in different
partitions. The AMD device only has the erase suspend feature. It can also suspend an
erase in Partition A and start writing to another block in Partition A. It resumes erase
once the write is completed. It is however, not possible to suspend an erase in partition B
for writing to another block in this partition.
Issue 1 11/02 ãNokia Corporation
RH-9
System Module & UI
Page 55