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8XC196K x , J x , CA USER'S MANUAL
16.1 PROGRAMMING METHODS
You can program the OTPROM by configuring a circuit that allows the device to enter a program-
ming mode. In programming modes, the device executes an algorithm that resides in the internal
test ROM.
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Slave programming mode allows you to use an EPROM programmer as a master to
program 8XC196 devices (the slaves). The code and data to be programmed into the
nonvolatile memory typically resides on a diskette. The EPROM programmer transfers the
code and data from the diskette to its memory, then manipulates the slave's pins to define
the addresses to be programmed and the contents to be written to those addresses. Using this
mode, you can program and verify single or multiple words in the OTPROM. This is the
only mode that allows you to read the signature word and programming voltages and to
program the PCCBs and unerasable PROM (UPROM) bits. Programming vendors and Intel
distributors typically use this mode to program a large number of microcontrollers with a
customer's code and data.
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Auto programming mode enables the 8XC196 device to act as a master to program itself
with code and data that reside in an external memory device. Using this mode, you can
program the entire OTPROM array except the UPROM bits and PCCBs. After
programming, you can use the ROM-dump mode to write the entire OTPROM array to an
external memory device to verify its contents. Customers typically use this low-cost method
to program a small number of microcontrollers after development and testing are complete.
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Serial port programming mode enables you to download code and data (usually from a
personal computer or workstation) to an 8XC196 device (the slave) through the serial I/O
port. You can write data to the OTPROM asynchronously via the TXD (P2.0) pin and read
the data via the RXD (P2.1) pin. Customers typically use this mode to download large
sections of code to the microcontroller during software development and testing.
You can also program individual OTPROM locations without entering a programming mode.
With this method, called run-time programming, your software controls the number and duration
of programming pulses. Customers typically use this mode to download small sections of code to
the microcontroller during software development and testing.
16.2 OTPROM MEMORY MAP
The OTPROM contains customer-specified special-purpose and program memory (Table 16-2).
The 128-byte special-purpose memory 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 16-2 to each reserved location.
The remainder of the OTPROM is available for code storage.
16-2
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