Samsung 8-Bit CMOS Microcontroller, S3C9228/P9228 user manual Operating Mode Characteristics

S3C9228/P9228 S3P9228 OTP

Table 18-1. Descriptions of Pins Used to Read/Write the EPROM

Main Chip			During Programming
Pin Name	Pin Name	Pin No.	I/O	Function
P1.2	SDAT	3 (9)	I/O	Serial data pin. Output port when reading and
				input port when writing. Can be assigned as a
				Input/push-pull output port.
P1.3	SCLK	4 (10)	I/O	Serial clock pin. Input only pin.
TEST	VPP(TEST)	9 (15)	I	Power supply pin for EPROM cell writing
				(indicates that OTP enters into the writing
				mode). When 12.5 V is applied, OTP is in
				writing mode and when 5 V is applied, OTP is in
				reading mode. (Option)
RESET	RESET	12 (18)	I	Chip initialization
VDD/VSS	VDD/VSS	5/6 (11/12)	I	Logic power supply pin. VDD should be tied to
				+ 5 V during programming.

NOTE: Parentheses indicate pin number for 42-SDIP package.

Table 18-2. Comparison of S3P9228 and S3C9228 Features

Characteristic	S3P9228	S3C9228
Program Memory	8 Kbyte EPROM	8 Kbyte mask ROM
Operating Voltage (VDD)	2.0 V to 5.5 V	2.0 V to 5.5 V
OTP Programming Mode	VDD = 5 V, VPP(TEST)=12.5V
Pin Configuration	44-QFP, 42-SDIP	44-QFP, 42-SDIP
EPROM Programmability	User Program 1 time	Programmed at the factory

OPERATING MODE CHARACTERISTICS

When 12.5 V is supplied to the VPP(TEST) pin of the S3P72C8, the EPROM programming mode is entered.

The operating mode (read, write, or read protection) is selected according to the input signals to the pins listed in Table 17-3 below.

Table 18-3. Operating Mode Selection Criteria

VDD	VPP (TEST)	REG/MEM	Address	R/W	Mode
			(A15-A0)
5 V	5 V	0	0000H	1	EPROM read
	12.5 V	0	0000H	0	EPROM program
	12.5 V	0	0000H	1	EPROM verify
	12.5 V	1	0E3FH	0	EPROM read protection

NOTE: "0" means Low level; "1" means High level.

18-3