BC352239A Datasheet, PDF (58/116 Pages) List of Unclassifed Manufacturers – BlueCore 3-Multimedia External

Device Terminal Descriptions
8.4 Off-Chip Program Memory
The external memory port provides a facility to interface up to 8Mbits of 16-bit external memory. This off-chip
storage is used to store BlueCore3-Multimedia External settings and program code. Flash is the storage
mechanism typically used by BlueCore3-Multimedia External modules, however external masked-ROM may also
be used if the host takes over responsibility for storing configuration data.
The external memory port consists of 16 bi-directional data lines, D[15:0]; 19 output address lines, A[18:0] and
three active low output control signals (WEB, CEB, REB). WEB is asserted when data is written to external
memory. REB is asserted when data is read from external memory and the chip select line. CSB is asserted
when any data transfer (read or write) is required. All of the external memory port connections are implemented
using CMOS technology and use standard 0V and VDD_MEM (1.8-3.6V) signalling levels.
Parameter
Data width
Minimum total capacity
Maximum access time
Value
16-bit
4Mbit (256kWord)
50ns @85°C 10pF load
Table 8.7: Flash Device Hardware Requirements
In addition to these hardware requirements, particular care should be taken to ensure that the sector organisation
of the extended memory has the correct format. A sector is defined as an individually erasable area of external
Flash.
It is important to make sure that external memory devices meet certain minimum specifications. In addition
particular care should be taken to ensure that the sector organisation of the extended memory has the correct
format.
Note:
The document “Selection of Flash Memory for Use with BlueCore”, (bcore-an-001Pd), provides guidance on
the selection of suitable flash devices for all BlueCore devices and should be read in conjuction with this
section.
BC352239A-ds-001Pc
© Cambridge Silicon Radio Limited 2004
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