W83627THF_06 Datasheet, PDF (85/142 Pages) Winbond – Winbond LPC I/O

W83627THF/W83627THG
CR26 (Default 0s000000b)
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. The corresponding power-on
setting pin is NRTSA (pin 51).
HEFRAS Address and Value
= 0 Write 87h to the location 2Eh twice.
= 1 Write 87h to the location 4Eh twice.
Bit 5 : LOCKREG
= 0 Enable R/W Configuration Registers
= 1 Disable R/W Configuration Registers.
Bit 4 : Reserved
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 electing 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
CR28 (Default 0x00)
Bit 7 - 3 : Reserved.
Bit 2 - 0 : PRTMODS2 - PRTMODS0
= 0xx Parallel Port Mode
= 100 Reserved
= 101 External FDC Mode
= 110 Reserved
= 111 External two FDC Mode
- 78 -