Chapter 3
Hardware
LittleBoard 800
Reference Manual
21
Note:
The shaded area denotes power or ground. The signals marked with * = Negative true logic.
Serial Interfaces
Two LPC47B272 chips provide the circuitry for the 4 serial ports. One chip provides serial ports 1 and 2
through connector J11 and the second chip provides serial ports 3 and 4 through connector J12. The four
serial ports support the following features:
•
Four individual 16550-compatible UARTs
•
Programmable word length, stop bits and parity
•
16-bit programmable baud rate generator
•
Interrupt generator
•
Loop-back mode
•
Four individual 16-bit FIFOs
3
PD0
I/O
Parallel Port Data 0 – These pins (0 to 7) provide parallel port data.
4
ERR*
Out
Error* – This is a status output signal from the printer. A Low State
indicates an error condition on the printer.
5
PD1
I/O
Parallel Port Data 1 – Refer to pin-3 for more information.
6
INIT*
Out
Initialize* – This signal used to Initialize printer. Output in standard
Mode, I/O in ECP/EPP mode.
7
PD2
I/O
Parallel Port Data 2 – Refer to pin-3 for more information.
8
SLIN
Out
Select In – This output signal is used to select the printer. I/O pin in
ECP/EPP mode.
9
PD3
I/O
Parallel Port Data 3 – Refer to pin-3 for more information.
10,
12
GND
Ground
11
PD4
I/O
Parallel Port Data 4 – Refer to pin-3 for more information.
13
PD5
I/O
Parallel Port Data 5 – Refer to pin-3 for more information.
14,
16
GND
Ground
15
PD6
I/O
Parallel Port Data 6 – Refer to pin-3 for more information.
17
PD7
I/O
Parallel Port Data 7 – Refer to pin-3 for more information.
18,
20
GND
Ground
19
ACK*
In
Acknowledge* – This printer output status indicates it has received
the data and is ready to accept new data if the signal state is Low.
21
BUSY
In
Busy – This printer output status indicates the printer is not ready to
accept data if the signal state is High.
22,
24
GND
Ground
23
PE
In
Paper End – The printer output status indicates the printer is out of
paper if the signal state is High.
25
SLCT
In
Select – This printer output status indicates the printer is selected and
powered on if the signal state is high.
26
Key/NC
Key - Not connected
Table 3-4. Parallel Interface Pin/Signal Descriptions (J16) (Continued)
Summary of Contents for LitleBoard 800
Page 1: ...LittleBoard 800 Single Board Computer Reference Manual P N 5001816B Revision A ...
Page 6: ...Contents vi Reference Manual LittleBoard 800 ...
Page 22: ...Chapter 2 Product Overview 16 Reference Manual LittleBoard 800 ...
Page 44: ...Chapter 3 Hardware 38 Reference Manual LittleBoard 800 ...
Page 48: ...Appendix A Technical Support 42 Reference Manual LittleBoard 800 ...
