Built-in PROM Version
M30240 Group
Rev.1.00 Sep 24, 2003 Page 348 of 360
5.1 Built-in PROM Version
The built-in PROM (programmable ROM) version has the same function as the mask ROM version. It is
possible to program the built-in PROM with a general purpose PROM programmer by using a
programming adapter that is suitable for the microcomputer.
Built-in PROM version is available in two types:
• One-time PROM version (OTP)
Possible to program in PROM once
Suitable for small quantities and various production.
• EPROM version
Possible to program in PROM repeatedly because a program can be erased by exposing the erase
window on the top of the package to an ultraviolet light source.
5.2 EPROM version
The EPROM version has the following two modes:
• Normal operating mode
Same functions as the mask ROM version
• EPROM mode
Programs to the built-in PROM. The built-in ROM version enters this mode when “L” level is input to
the RESET pin and P6
2
pin.
5.2.1 EPROM mode pins
5.2.1.1 Pin Functions
Table 5.1 lists the pin functions in the EPROM mode. In normal operating mode, each pin has the
same function as the mask ROM version.
Table 5.1: Pin functions in EPROM mode
Pin Name
Input/
Output
Functions
Vcc, Vss Power source --- Apply 5V +/- 10% to the Vcc pin and 0V to the Vss pin
CNVss Vpp Input Input Apply Vpp when programming or verifying
RESET Reset input Input Connect to Vss pin.
X
IN
Clock input Input
Connect X
IN
pin and X
OUT
pin via a ceramic resonator or
quarts-crystal oscillator. When an externally generated
clock is used, input the clock to the X
IN
pin and leave the
X
OUT
pin open.
X
OUT
Clock output Output
BYTE --- Input Connect to Vcc pin.
AVcc
Analog power source input ---
Connect to Vcc pin.
AVss Connect to Vss pin.
Vref Reference voltage input Input Connect to Vcc pin.
P0
0
to P0
7
Data input/output (D0 to D7) I/O 8-bit data (D0 to D7) input/output pin
P1
0
to P1
7
Address input (A8 to A15) I/O The middle order 8-bit (A8 to A15) address input pins.
P2
0
to P2
7
Address input (A0 to A7) I/O The low-order 8-bit (A0 to A7) address input pins.
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