W83637HF Datasheet, PDF (108/149 Pages) Winbond – LPC I/O

W83637HF
CR26 (Default 0b0s000000)
Bit 7 : SEL4FDD
= 0 Select two FDD mode.
= 1 Select four FDD mode.
Bit 6
: HEFRAS
These two bits define how to enable Configuration mode.
setting pin is NRTSA (pin 51).
HEFRAS Address and Value
= 0 Write 87h to the location 2E twice.
= 1 Write 87h to the location 4Etwice.
The corresponding power-on
Bit 5
: LOCKREG
= 0 Enable R/W Configuration Registers
= 1 Disable R/W Configuration Registers.
Bit 4 :Reserve
Bit 3
: DSFDLGRQ
= 0 Enable FDC legacy mode on IRQ and DRQ selection, then DO register bit 3 is
effective on selecting IRQ
= 1 Disable FDC legacy mode on IRQ and DRQ selection, then DO register bit 3 is
not effective on selecting IRQ
Bit 2
: DSPRLGRQ
= 0 Enable PRT legacy mode on IRQ and DRQ selection, then DCR bit 4 is effective
on selecting IRQ
= 1 Disable PRT legacy mode on IRQ and DRQ selection, then DCR bit 4 is not
effective on selecting IRQ
Bit 1
: DSUALGRQ
= 0 Enable UART A legacy mode IRQ selecting, then MCR bit 3 is effective on
selecting IRQ
= 1 Disable UART A legacy mode IRQ selecting, then MCR bit 3 is not effective on
selecting IRQ
Bit 0
: DSUBLGRQ
= 0 Enable UART B legacy mode IRQ selecting, then MCR bit 3 is effective on
selecting IRQ
= 1 Disable UART B legacy mode IRQ selecting, then MCR bit 3 is not effective on
selecting IRQ
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Publication Release Date: June 25, 2003
Revision 1.3