FLASH MEMORY VERSION
19.3 Flash memory serial I/O mode
(2) With control signals affecting user system circuit
In the flash memory serial I/O mode, be sure to cut the current flow toward the user system circuit
if control signals for this mode are also used in the user system circuit. Figure 19.3.4 shows an
example of handling pins with jumper switches used, and Figure 19.3.5 shows an example of handling
pins with analog switches used.
User system board
Connected to the user system circuit.
M37905F❈
SDA(P2
BUSY(P2
SCLK(P2
5
)
6
)
)
VCC
4
P4OUTCUT, P6OUTCUT (Note 1)
MD0
Connected to
serial progra-
mmer.
MD1
VSS
RESET
XIN
X
OUT
User reset signal (Note 2)
Note 1: Recommended to be connected with VCC via a resistor.
2: When there is a possibility that the user reset signal becomes “L” level in the flash memory serial I/O mode,
be sure to cut the current flow between the user reset pin and pin RESET by using a jumper switch, etc.
❈: The flash memory version of the 7905 Group
Fig. 19.3.4 Example of handling pins with jumper switches used
User system board
74 HC4066
Connected to the user system circuit.
M37905F❈
SDA(P25)
BUSY(P2
SCLK(P2
6
4
)
)
VCC
Connected to
serial progra-
mmer.
MD0
P4OUTCUT, P6OUTCUT (Note 1)
VSS
MD1
RESET
X
IN
XOUT
User reset signal (Note 2)
Note 1: Recommended to be connected with VCC via a resistor.
2: When there is a possibility that the user reset signal becomes “L” level in the flash memory serial I/O mode,
be sure to cut the current flow between the user reset pin and pin RESET by using a jumper switch, etc.
❈: The flash memory version of the 7905 Group
Fig. 19.3.5 Example of handling pins with analog switches used
7905 Group User’s Manual Rev.1.0
19-24
RENESAS [ RENESAS TECHNOLOGY CORP ]
