Nokia Mobile Phones NSE-5 Series Service Manual page 61

PAMS
Technical Documentation
MCU Memory Requirements
The MCU memory requirements are shown below.
Product Device
DCT3.5
DCT3.5
Flash Programming
The system connector can be used as a flash prom programming
interface for flash memories for updating (i.e. re–programming) the flash
program memory. Used system connector pins and their functions are
listed in Table 3.
To flash the phone use service battery (BBD–3) this will automatically
power up the phone via BTEMP. When flashing, the phone has to be
initialised after each file has been flashed. The flash prommer controls the
power up of the phone via the service battery.
The program execution starts from the BOOT ROM and the MCU
investigates in the early start–up sequence if the flash prommer is
connected. This is done by checking the status of the MBUS–line.
Normally this line is high but when the flash prommer is connected the
line is forced low by the prommer. The flash prommer serial data receive
line is in receive mode waiting for an acknowledgement from the phone.
The data transmit line from the baseband to the prommer is initially high.
When the baseband has recognized the flash prommer, the FBUS TX–line
is pulled low. This acknowledgement is used to start the data transfer of
the first two bytes from the flash prommer to the baseband on the FBUS
RX–line. The data transmission begins by starting the serial transmission
clock (MBUS–line) at the prommer.
The 2.8V programming voltage is supplied inside the transceiver from the
CCONT.
For protecting the MAD2PR1 against ESD spikes at the system connector,
the data transmission lines (MBUS, RX and TX) are equipped with EMI
fitters.
Issue 1 07/99
Table 13. HD945 Memory Requirements
Organiza-
tion
ROM 2Mx16
SRAM 256Kx8
Ac- Wait
cess States
Time Used
ns
100 1 2.8V/2.8V Read/Write
85 1 120ns @ 2.8V Read/Write
NSE–5
System Module
Remarks
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