FLASH MEMORY VERSION
7902 Group User’s Manual
20-27
20.3 Flash memory serial I/O mode
Table 20.3.1 Pin description in flash memory serial I/O mode
Supply VCC level voltage to pin Vcc.
Supply VSS level voltage to pin Vss.
Connect this pin to VSS.
Connect this pin to VSS via a resistor (about 10 k
to 100 k).
The BYTE pin. (Not used in this mode.)
The reset input pin (Note 1).
Connect a ceramic resonator or quartz-crystal oscillator between
XIN and XOUT pins. When using an external clock, the clcok source
must be input to XIN pin and XOUT pin must be left open.
Connect this pin to VCC, or leave it open.
The VCONT pin. (Not used in this mode.)
Connect this pin to VCC.
Connect this pin to VSS.
The VREF pin. (Not used in this mode.)
Input port pins. (Not used in this mode.)
The input pin for a serial clock.
The I/O pin for serial data. This pin must be connected to an external
pullup resistor (about 1 k
).
The BUSY signal output pin.
Input port pins. (Not used in this mode.)
VCC
VSS
MD0
MD1
BYTE
RESET
XIN
XOUT
NMI
VCONT
AVCC
AVSS
VREF
P00 to P07
P10 to P17
P20 to P27
P30 to P33
P40,
P44 to P47
P41
P42
P43
P50 to P57
P60 to P67
P70 to P77
P80 to P87
P100 to P107
P110 to P117
Input
Output
Input
—
Input
I/O
Output
Input
Pin
Name
Input/Output
Functions
Power supply input
MD0
MD1
External data bus
width select input
Reset input
Clock input
Clock output
NMI interrupt input
Filter circuit connection
Analog supply input
Reference voltage input
Input port P0
Input port P1
Input port P2
Input port P3
Input port P4
SCLK input
SDA I/O
BUSY output
Input port P5
Input port P6
Input port P7
Input port P8
Input port P10
Input port P11
Notes 1: 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 off the current flow between the user reset signal and pin RESET by using a
jumper switch, etc. (Refer to section “19.2 Examples of handling control pins in flash memory
serial I/O mode.”)
2: For pins not used in the flash memory serial I/O mode, properly connect to somewhere in the user
system. For pins not used in the user system, handle them with reference to section “6.3 Examples of
handling unused pins.” For pins used in the flash memory serial I/O mode, handle them with reference
to section “19.2 Examples of handling control pins in flash memory serial I/O mode.”