© 1999 Scenix Semiconductor, Inc. All rights reserved. - 13 - www.scenix.com SX18AC  / SX20AC / SX28AC 5.2    FUSEX Word (Read/Program via Programming Command) 5.3    DEVICE Word (Hard-Wired Read-Only) IRCTRI M2 Preset IRCTRI M1 IRCTRI M0 Preset CF BOR1 BOR0 RAM1 RAM0 MEM1 MEM0 Bit 11 Bit 0 IRCTRIM2:
IRCTRIM0 Internal RC oscillator trim bits. This 3-bit field adjusts the operation of the internal RC oscillator to make
it operate within the target frequency range 4 MHz plus or minus 8%. Parts are shipped from the factory
untrimmed. The device relies on the programming toll to provide the trimming function.
000b = minimum frequency
111b = maximum frequency
each step about 3% CF                               active low – makes carry bit input to ADD and SUB instructions.
BOR1: BOR0   Brown-Out Reset; Factory preset values. Bits should not be changed unless brown-out feature is to be                               disabled.
                              00b = Brown-Out enabled (4.2V trip point)
                              01b = Reserved
                              10b = Resrved
                              11b = Brown-Out disabled
RAM1: RAM0  Configured number of RAM banks on chip:                               00b = 1 bank
                              01b = 2 banks
                              10b = 4 banks
                              11b = 8 banks
MEM1:MEM0  Configured memory size on chip Pages 00b = 1 Each page is 512 words 01b = 2 10b = 4 11b = 4 (default configuration) Res. Res. Res. Res. Res. Res. Res. Res. RAM1 RAM0 MEM1 MEM0 Bit 11 Bit 0 Res. Reserved bit that reads “1” RAM1:RAM0 Absolute number of RAM banks on chip:
00b = 1
01b = 2
10b = 4
11b = 8 banks MEM1:MEM0  Absolute memory size on chip:
00b = 512 words
01b = 1024 words
10b = 2048 words
11b = 4096 words  (Reserved)