W90210F Winbond Electronics Corp America, W90210F Datasheet - Page 36

• Manufacturer Part Number: W90210F
• Description: Pa-risc Embedded Controller
• Manufacturer: Winbond Electronics Corp America

speed bi-directional communication between the PC and an external peripheral.
the forward direction, reverse direction, or bi-directional data transfer. The defined modes are:
8.5 Parallel Port
This is the standard parallel port data register. Writing to this register in Standard mode shall drive data to the
parallel port data lines. In all other modes the drivers may be tri-stated by setting the direction bit in the dcr
register. Read to this register return the value on the data lines.
This read-only register reflects the inputs on the parallel port interface.
This register directly controls several output signals as well as enabling some functions. The drivers for nStrobe,
nAutoFd, nInit, and nSelectIn are open-collector in standard mode.
The parallel port megacell implements the IEEE 1284 parallel port. The IEEE 1284 standard provides for high
The parallel port defines 5 modes of data transfer. Each mode provides a method of transfering data in either
Other modes defined in the IEEE 1284 standard like test mode and configuration mode are also supported.
8.5.1 ECP Register Description
1. Data Register (offset 378) R/W
Standard mode:
PS/2 mode, forward:
PS/2 mode, reverse:
Centronix Peripheral mode:
2. DSR register (offset 379) Read only
Bit [0]- nBusy:
Bit [1]- nAck:
Bit [2]- PError:
Bit [3]- Select:
Bit [4]- nFault:
Bit [5:7]- reserved
3. DCR register (offset 37a) R/W
Bit [0:1]- reserved
Bit [2]- Direction
Other mode:
0
0
0
0: forward (default)
1: reserved
The above information is the exclusive intellectual property of Winbond Electronics Corp. and shall not be disclosed, distributed or reproduced without permission from Winbond.
Standard parallel port mode
PS/2 parallel port mode
Parallel port FIFO mode
ECP parallel port mode
Centronix Peripheral mode (Vendor specified mode)
write data_reg: cpu_data[0:7]
read data_reg: data_reg[0:7]
write data_reg: cpu_da ta
read data_reg: data_reg
write data_reg: cpu_data
read data_reg: PAD_ED
read data_reg: PAD_ED
write data_reg: cpu_data[0:7]
read data_reg: undefined
Drivers are enabled.
inverted parallel port
parallel port
parallel port
parallel port
parallel port
nAck
PError
Select
nFault
signal
signal
signal
signal
cpu_data
cpu_data
cpu_data
data_reg
data_reg
Busy
cpu_data
36
data_reg[0:7]
data_reg[0:7]
7
7
7
signal
PAD_ED
PAD_ED[0:7]
W90210F
Version 1.4, 10/8/97