BIT 3 READ DATA TOGGLE
Every inactive edge of the RDATA input causes this bit to change state.
BIT 4 WRITE DATA TOGGLE
Every inactive edge of the WDATA input causes this bit to change state.
BIT 5 DRIVE SELECT 0
Reflects the status of the Drive Select 0 bit of the DOR (address 3F2 bit 0). This bit is cleared after a hardware reset
and it is unaffected by a software reset.
BIT 6 RESERVED
Always read as a logic "1".
BIT 7 RESERVED
Always read as a logic "1".
PS/2 Model 30 Mode
7
6
5
4
3
2
1
0
nDRV2 nDS1
nDS0 WDATA RDATA WGATE nDS3
nDS2
F/F
0
F/F
0
F/F
0
RESET
COND.
N/A
1
1
1
1
BIT 0 nDRIVE SELECT 2
The DS2 disk interface is not supported.
BIT 1 nDRIVE SELECT 3
The DS3 disk interface is not supported.
BIT 2 WRITE GATE
Active high status of the latched WGATE output signal. This bit is latched by the active going edge of WGATE and is
cleared by the read of the DIR register.
BIT 3 READ DATA
Active high status of the latched RDATA output signal. This bit is latched by the inactive going edge of RDATA and is
cleared by the read of the DIR register.
BIT 4 WRITE DATA
Active high status of the latched WDATA output signal. This bit is latched by the inactive going edge of WDATA and
is cleared by the read of the DIR register. This bit is not gated with WGATE.
BIT 5 nDRIVE SELECT 0
Active low status of the DS0 disk interface output.
BIT 6 nDRIVE SELECT 1
Active low status of the DS1 disk interface output.
BIT 7 nDRV2
Active low status of the DRV2 disk interface input. Note: This function is not supported.
DIGITAL OUTPUT REGISTER (DOR)
Address 3F2 READ/WRITE
The DOR controls the drive select and motor enables of the disk interface outputs. It also contains the enable for the
DMA logic and a software reset bit. The contents of the DOR are unaffected by a software reset. The DOR can be
written to at any time.
7
6
5
4
3
2
1
0
MOT
MOT
MOT
MOT
DMAEN
nRESET
DRIVE
DRIVE
EN3
EN2
EN1
EN0
SEL1
SEL0
RESET
COND.
0
0
0
0
0
0
0
0
SMSC DS – LPC47M14X
Page 29
Rev. 03/19/2001
SMSC [ SMSC CORPORATION ]
