Lucent Technologies MN10285K - Manual (Page 326)

MN102HF75K Flash EEPROM Version
Using the Onboard Serial Programming Mode
MN102H75K/F75K/85K/F85K LSI User Manual Panasonic Semiconductor Development Company
325
Panasonic
B.4.6 Setting Up the Onboard Serial Programming Mode
To enter serial programming mode, the microcontroller must be in write mode.
This section describes the pin setup for the serial writer interface.
■ To set up the serial writer interface:
1. Turn on the external V
DD
supply.
2. At time A in figure B-8, turn V
PP
on. At this point, output RST = SBD = low.
3. Through the serial writer, drive the RST pin from time B in figure B-8, when
SBT goes high on microcontroller power-up, for t
2
cycles. The microcontrol-
ler initializes.
4. Through the serial writer, drive the SBD pin low from time C in figure B-8,
when RST goes high on microcontroller power-up, for t
3
cycles. This tells
the microcontroller that it is connected to the serial writer.
5. Make t
3
long enough to allow the microcontroller oscillator to stabilize.
Figure B-8 Timing for the Serial Writer Interface
SBT
SBD
SBT
SBD
t 1 t 2
A B C
Timing waveform during
serial programming
Normal timing waveform
RST
V
DD
D
RST
V DD
t 3
V
PP
V
PP