Changing Serial Port Programming Defaults - Intel 8XC196K Series User Manual

8XC196K x , J x , CA USER'S MANUAL
Because the RISM begins at location 2000H in serial port programming mode, the OTPROM lo-
cations are automatically remapped as shown in Table 16-12. For example, to access OTPROM
location 2000H in serial port programming mode, you must address it as A000H.
Table 16-12. Serial Port Programming Mode Memory Map
Description
Internal OTPROM
External memory
Do not address
Test ROM and RISM
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For the 87C196JV, the lower 24 Kbytes of internal OTPROM (2000–7FFFH) are remapped to A000–
FFFFH. The upper 24 Kbytes must be addressed as 8000–DFFFH. A bank switching mechanism differen-
tiates between the two address ranges. To program the upper 24 Kbytes of the internal OTPROM, execute
this instruction: orb tmr, #80h.
††
For the 87C196CA, JT, and KT, the lower 24 Kbytes of internal OTPROM (2000–7FFFH) are remapped to
A000–FFFFH. The upper 8 Kbytes must be addressed as 8000–9FFFH.

16.10.2 Changing Serial Port Programming Defaults

Several locations in test ROM are used to control operating parameters. The test ROM routine
establishes the default values shown in Table 16-13. To change the default values, write the de-
sired values to the test ROM addresses shown in the table. (Refer to the SP_BAUD, SP_CON,
and SP_PPW register descriptions in Appendix C.) After you write the new values to the test
ROM locations, the RISM writes the programmed values into the associated registers.
The default programming pulse width is longer than required. To avoid unnecessarily long pro-
gramming times, change the default value before beginning to program the device. For a 100-µs
pulse width, use the following formula to determine the required PPW_VALUE and write that
value to the test ROM location listed in Table 16-13.
(
PPW_VALUE
=
16-34
Device
87C196JV
87C196CA, JT, KT
87C196KS
87C196JR, KR
87C196JQ, KQ
87C196CA, JT, KT, JV
87C196JQ, KQ, JR, KR, KS
All
All
× )
0.6944 F 1
–
osc
Address Range (Hex)
Normal Serial Port
Operation Programming Mode
2000–DFFF A000–FFFF, 8000–DFFF
2000–9FFF A000–FFFF, 8000–9FFF
2000–7FFF A000–FFFF
2000–5FFF A000–DFFF
2000–4FFF A000–CFFF
— 4000–7FFF
— 4000–9FFF
— 2400–3FFF
— 2000–23FF
†
††