Intel 8XC196Lx Programming the Nonvolatile Memory, Signature Word and Programming Voltage Values

CHAPTER 11 PROGRAMMING THE NONVOLATILE MEMORY

The 87C196LA and LB microcontrollers contain 24 Kbytes (2000–7FFFH) of one-time-pro- grammable read-only memory (OTPROM). OTPROM is similar to EPROM, but it comes in a windowless package and cannot be erased. You have the option of programming the OTPROM yourself or having the factory program it as a quick-turn ROM product (the latter option may not be available for all devices).

NOTE

In this supplement, OTPROM refers to the device’s internal read-only memory, whether it is EPROM or OTPROM, and EPROM refers specifically to EPROM devices.

The 87C196LA and LB programming signals, registers, and procedures are the same as those of the 87C196Kx. This chapter describes the differences in memory mapping and programming cir- cuits for the 87C196LA and LB.

11.1 SIGNATURE WORD AND PROGRAMMING VOLTAGE VALUES

The 8XC196Lx’s programming voltage values are the same as those of the 8XC196K x; however, the signature word value differs. Table 11-1 lists the signature word and programming voltage values.

Table 11-1. Signature Word and Programming Voltage Values

	Device	Signature Word		Programming VCC		Programming VPP
		Location	Value	Location	Value	Location	Value
87C196LA		0070H	871BH	0072H	40H	0073H	0A0H
87C196LB		0070H	871BH	0072H	40H	0073H	0A0H

11.2 OTPROM ADDRESS MAP

The OTPROM contains customer-specified special-purpose and program memory (Table 11-2). The 128-byte special-purpose address partition is used for interrupt vectors, the chip configura- tion bytes (CCBs), and the security key. Several locations are reserved for testing or for use in future products. Write the value (20H or FFH) indicated in Table 11-2 to each reserved location. The remainder of the OTPROM is available for code storage.

11-1