
MFC2000 Multifunctional Peripheral Controller 2000
Hardware Description
17-8
Conexant
100723A
NCMD
Command
When read, this bit provides the logic level of the AUTOFDn pin when
STROBEn (hostClk) transitioned from high to low with PDOE clear. If
set, AUTOFDn was latched high. If low, AUTOFDn was latched low.
This is a read-only data bit. Writing NCMD has no effect.
Parallel Port ACK Pulse Width Register
The Parallel Port ACK Pulse Width Register is an 8-bit read/write register that defines the pulse width of ACKn
during compatibility mode (MODE = 1), and setup timing relative to ACKn during reverse transfer modes
(MODE=4,4,6). The Parallel Port ACKn Pulse Width Register can be written and rewritten to program different
timing values as transitions are made to new transfer modes.
An ACKn pulse width can be programmed to be 0 to 255 IHSCLK periods wide. At 20MHZ, this allows software to
set pulse widths anywhere in the range of 0 to 12.75us. If ACKW is set to zero, no ACKn pulse is generated at the
end of compatibility mode cycles.
Setup timing relative to ACKn during reverse transfer modes can be programmed to be 1 to 256 IHSCLK periods.
During nibble or byte modes(MODE=4,5), ACKW defines the setup timing from nibble or byte data (event 8 or 15)
and the falling edge of ACKn (event 9), or from peripheral status (event 13) to the rising edge of ACKn (event 11).
During ECP reverse transfers (MODE = 6), ACKW defines the setup timing from reverse data (event 42) to the
falling edge of ACKn (event 43).
Address
Bit 15
(Not Used)
Bit 14
(Not Used)
Bit 13
(Not Used)
Bit 12
(Not Used)
Bit 11
(Not Used)
Bit 10
(Not Used)
Bit 9
Bit 8
Default
Rst. Value
xxh
Read Value
00h
Parallel Port ACK
Pulse Width Reg.
(PIOAckPW)
$01FF8207
(Not Used)
(Not Used)
Address
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Default
Rst. Value
00h
Read Value
00h
Parallel Port ACK
Pulse Width Reg.
(PIOAckPW)
$01FF8206
ACKW(7)
ACKW(6)
ACKW(5)
ACKW(4)
ACKW(3)
ACKW(2)
ACKW(1)
ACKW(0)
ACKW
ACKn Pulse Width
This 8 bit field defines the pulse width of ACKn during compatibility
mode transfers (MODE = 1), and the setup relationship relative to
ACKn during reverse transfer modes (MODE=4,5,6). A pulse width
from 0 to 255 IHSCLK periods can be programmed.
Parallel Port Reverse Data Status Register
Address
Bit 15
(Not Used)
Bit 14
(Not Used)
Bit 13
(Not Used)
Bit 12
(Not Used)
Bit 11
(Not Used)
Bit 10
(Not Used)
Bit 9
Bit 8
Default
Rst. Value
xxh
Read Value
00h
Parallel Port Reverse
Data Status Reg.
(PIORevDataSTS)
$01FF8209 (R)
(Not Used)
(Not Used)
Address
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Default
Rst. Value
00h
Read Value
00h
Parallel Port Reverse
Data Status Reg.
(PIORevDataSTS)
$01FF8208 (R)
RVDAT(7)
RVDAT(6)
RVDAT(5)
RVDAT(4)
RVDAT(3)
RVDAT(2)
RVDAT(1)
RVDAT(0)
REVDATA
Reverse Data
This 8-bit field is the status of the reverse data that was written into the
Parallel Port Data Register oppid[7:0]. This normally is needed only for
diagnostic purposes. This is a read-only status register.