mcs7717 MosChip, mcs7717 Datasheet - Page 28

• Manufacturer Part Number: mcs7717
• Description: Three Port Usb Hub With 1 Serial, 1 Printer
• Manufacturer: MosChip

Page 28
MCS7717
Three Port USB Hub with 1 Serial, 1 Printer
Parallel Printer Port Register Descriptions
Data Register
The Data Register is cleared at initialization by RESET. During a write operation, the contents of this register
are buffered and output onto the PD7-PD0 ports. During a read operation PD7-PD0 ports are buffered and
output to the host CPU.
Register:
Description:
Offset:
Permissions:
Access Condition:
Device Status Register
The bits of the status register are defined as follows:
Register:
Description:
Offset:
Permissions:
Access Condition:
Note: Bit-7 (nBUSY) in this register is logically inverted from the state of the electrical signal appearing at the
physical device pin. When the printer is BUSY, this bit will read back as a zero.
Bit
7*
0
1
2
3
4
5
6
nBUSY
Bit[7]
Bit[7]
nFAULT
Unused
Unused
Unused
nBUSY
Name
SLCT
nACK
PE
PP_DPR
Parallel Printer Data Register
000
Read/Write
Application Number = 0x0100
DSR
Device Status Register
001
Read
Application Number = 0x0100
nACK
Bit[6]
Bit[6]
Not used, set to 0
Not used, set to 0
Not used, set to 0
Logic 0 = Printer reports an error condition exists.
Logic 1 = Normal operation.
Logic 0 = Printer is off line.
Logic 1 = Printer is on line.
Logic 0 = Normal operation
Logic 1 = Paper end/empty is detected
Logic 0 = State of the nACK pin (nACK = Low).
Logic 1 = State of the nACK pin (nACK = High).
Logic 0 = BUSY pin is high, printer is not ready to take data.
Logic 1 = BUSY pin is low, printer is ready to take data.
Bit[5]
Bit[5]
PE
Parallel Printer Data
Bit[4]
Bit[4]
SLCT
nFAULT
Description
Bit[3]
Bit[3]
Unused
Bit[2]
Bit[2]
Unused
Bit[1]
Bit[1]
Unused
Bit[0]
Bit[0]
Rev. 1.7