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8XC196K x , J x , CA USER'S MANUAL
16.10 SERIAL PORT PROGRAMMING MODE
The serial port programming mode enables the serial I/O (SIO) port to write data to the OTPROM
through the TXD (P2.0) pin and read it through the RXD (P2.1) pin. In this mode, the device ex-
ecutes a program from its internal test ROM. This program is a modified version of the reduced
instruction set monitor (RISM) that exists on all 8X9X evaluation boards. The simple hardware
setup of this mode makes it useful for in-module testing, programming, and in-line diagnostics.
Special software, called IBSP196, simplifies communication between the device and a smart ter-
minal. This software is available free of charge through the Intel BBS. (See "Bulletin Board Sys-
tem (BBS)" on page 1-9.)
Serial port programming mode has no provision for security-key verification.
If a security key has been programmed, an attempt to enter serial port
programming mode causes the device to enter an endless loop.
Entering serial port programming mode with V
OTPROM or to program small segments of OTPROM to customize code for a particular module.
(Programming more than 2 Kbytes of OTPROM is not recommended in this mode because of its
relatively long programming time.)
Entering serial port programming mode with V
tions:
•
download a module-testing program into internal RAM and execute it without altering
nonvolatile memory or using dedicated OTPROM software space
•
run a segment of code in OTPROM and monitor its performance during execution
•
examine the code programmed into the OTPROM
•
examine the contents of any register
•
manipulate RAM, SFRs, or pin states
16.10.1 Serial Port Programming Circuit and Memory Map
Figure 16-14 shows the recommended circuit for serial port programming. In this mode, data is
transmitted and received through the TXD (P2.0) and RXD (P2.1) pins. Connect these pins to any
smart terminal capable of communicating with the RISM. Any host that requires an RS-232C in-
terface (such as a PC) must be connected through an RS-232C driver/receiver such as the one
shown within the dashed line in Figure 16-14. XTAL1 and XTAL2 can be connected to a crystal
with a frequency between 3.5 MHz and 16 MHz. The frequency must correspond to the value in
the SP_BAUD register (see "Changing Serial Port Programming Defaults" on page 16-34).
16-32
NOTE
at +12.5 volts allows you to modify code in
PP
at +5.0 volts enables you to perform these func-
PP
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