11-1
CHAPTER 11PROGRAMMING 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 8XC196Kx; however,
the signature word value differs. Table 11-1 lists the signature word and programming voltage
values.
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.
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