Beijing Rongda science & Technology RD-EK32 Series, Development Manual

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RD-EK32 Series User Development manual
7
2
，
6
，
8
NC
— — — —
10
～
24 GND
— —
Signal ground 12
、
25
Note
：①
The mainframe and printer in the item ‘ signal source‟ means the source of the signal sending out
信号来源一项中的
“
打印机
”
和
“
主机
”
表示信入发出的来源。
②
The signal logic level is
EIA
level.
信号逻辑电平为
EIA
电平。
2.2.2 Parallel interface data transmission method
Using parallel interface to send data is more complicated than using serial interface,
because using parallel interface to send data need the cooperation of the
‘STB’,‘BUSY’ AND
‘DATA’ data wires.
See figure 3-4
并口数据的发送相对来说比串口要麻烦些，需要
STB
，
BUSY
及
DATA
数据线之间的时序配合，
才可以发送，图
3-4
为并口发送一字节的时序图。
Sending step:
step1: using the appropriate data wire connects the printer to PC
step2:power on the printer and load the printing paper
step3:Begin to transmit data
，
and flow chart is as follows:
图
3-4
Initialization:
BUSY=1
，
STB=1
BUSY=1
Sending 8 bits data to
the printer interface
STB=0;
Delay Time
≥
0.5us;
STB=1
；
N
Y
Whether to end
sending the data
End printing
Y
N