W83977ATF Datasheet, PDF (133/207 Pages) Winbond – WINBOND I/O

W83977ATF
PRELIMINARY
Bit 6: EN48
= 0 The clock input on Pin 1 should be 24 Mhz.
= 1 The clock input on Pin 1 should be 48 Mhz.
The corresponding power-on setting pin is SOUTB (pin 53).
Bit 5 - 3: Reserved.
Bit 2: ENKBC
= 0 KBC is disabled after hardware reset.
= 1 KBC is enabled after hardware reset.
This bit is read only, and set/reset by power-on setting pin. The corresponding power-on
setting pin is SOUTA (pin 46).
Bit 1: Reserved
Bit 0: PNPCSV
= 0 The Compatible PnP address select registers have default values.
= 1 The Compatible PnP address select registers have no default value.
When trying to make a change to this bit, new value of PNPCSV must be complementary
to the old one to make an effective change. For example, the user must set PNPCSV to 0
first and then reset it to 1 to reset these PnP registers if the present value of PNPCSV is 1.
The corresponding power-on setting pin is NDTRA (pin 44).
CR25 (Default 0x00)
Bit 7 - 6: Reserved
Bit 5: URBTRI
Bit 4: URATRI
Bit 3: PRTTRI
Bit 2: IRTRI
Bit 1: Reserved
Bit 0: FDCTRI.
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. The corresponding power-on
setting pin is NRTSA (pin 43).
HEFRAS Address and Value
= 0 Write 87h to the location 3F0h twice.
= 1 Write 87h to the location 370h twice.
Bit 5: LOCKREG
= 0 Enable R/W Configuration Registers.
= 1 Disable R/W Configuration Registers.
Bit 4: DSIRLGRQ
= 0 Enable IR legacy mode IRQ selecting, then MCR bit 3 is effective on selecting
IRQ
= 1 Disable IR legacy mode IRQ selecting, then MCR bit 3 is not effective on
selecting IRQ
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Publication Release Date: Auguest 1997
Revision 0.51