NAME
REG INDEX
DEFINITION
STATE
Forced Disk Change
0xC1 R/W
Force Change 1 and Force Change 0 can be
written to 1 are not clearable by software.
Force Change 1 is cleared on (nSTEP AND nDS1)
Force Change 0 is cleared on (nSTEP AND nDS0).
DSK CHG (Floppy DIR Register, Bit 7) = (nDS0
AND Force Change 0) OR (nDS1 AND Force
Change 1) OR nDSKCHG.
Default = 0x03
on VTR POR
Setting either of the Force Disk Change bits active
(1) forces the FDD nDSKCHG input active when
the appropriate drive has been selected.
Bit[0] Force Change for FDC0
0=Inactive
1=Active
Bit[1] Force Change for FDC1
0=Inactive
1=Active
Bit[2:7] Reserved, Reads 0
Floppy Data Rate Select Shadow Register
Bit[7] Soft Reset
Bit[6] Power Down
Bit[5] Reserved
Bit[4] PRECOMP 2
Bit[3] PRECOMP 1
Bit[2] PRECOMP 0
Bit[1] Data Rate Select 1
Bit[0] Data Rate Select 0
UART1 FIFO Control Shadow Register
Bit[7] RCVR Trigger MSB
Bit[6] RCVR Trigger LSB
Bit[5] Reserved
Floppy Data Rate
Select Shadow
0xC2 R
0xC3 R
0xC4 R
UART1 FIFO
Control Shadow
Bit[4] Reserved
Bit[3] DMA Mode Select
Bit[2] XMIT FIFO Reset
Bit[1] RCVR FIFO Reset
Bit[0] FIFO Enable
UART2 FIFO Control Shadow Register
Bit[7] RCVR Trigger MSB
Bit[6] RCVR Trigger LSB
Bit[5] Reserved
UART2 FIFO
Control Shadow
Bit[4] Reserved
Bit[3] DMA Mode Select
Bit[2] XMIT FIFO Reset
Bit[1] RCVR FIFO Reset
Bit[0] FIFO Enable
199
SMSC [ SMSC CORPORATION ]
