On Board Writing - Samsung S3C9228 User Manual

S3C9228/P9228_UM_REV1.10

ON BOARD WRITING

The S3P9228 needs only 6 signal lines including V
protocol. Therefore the on-board writing is possible if the writing signal lines are considered when the PCB of
application board is designed.
Circuit design guide
At the flash writing, the writing tool needs 6 signal lines that are V
When you design the PCB circuits, you should consider the usage of these signal lines for the on-board writing.
In case of TEST pin, normally test pin is connected to V
a resistor should be inserted between the TEST pin and V
under the same consideration.
Please be careful to design the related circuit of these signal pins because rising/falling timing of V
SDAT is very important for proper programming.
SCLK(I/O)
SDAT(I/O)
nRESET
V (TEST)
PP
V
DD
V
SS
C V
C nRESET
PP
V
PP
V
nRESET
DD
GND
SPW-uni , GW-uni
Figure 18-4. PCB Design Guide for on Board Programming
and V pins for writing internal flash memory with serial
DD SS
, V , nRESET, TEST, SDAT and SCLK.
SS DD
but in writing mode the programming these two cases,
SS
. The nRESET, SDAT and SCLK should be treated
SS
R
SCLK
R
SDAT
R
nRESET
R
V
PP
SDAT
SCLK
C nRESET and C V
improve the noise effect.
, AS-pro, US-pro
S3P9228 OTP
, SCLK and
PP
To Application circuit
To Application circuit
To Application circuit
are used to
PP
18-5