Programmable Parallel
KR580VV55A interface.
(C) AlphA Studio
In this short article I want to talk about
chip set which, in its complex
You can solve many problems with the connection
external devices. This parallel port
KR580VV55A. In some computers, the port
originally installed, and some even
not one. With this chip easily
connected printer, programmer, and video port and an optional
joystick.
For interfacing external devices (ED) with
data bus and a programmable microprocessor parallel interface
(PPI) has three 8-bit port A, B and C. Controlled
channels on the program by issuing a control word, which
contains information about mode and the set or reset
individual bits of the channel C. The PPI can operate in three
modes: 0 - basic input-vyvad channels A, B and C;
1 - I / O channels with gating
A and B;
2 - dvunopravlennaya bus with a strobe
cm channel A.
In most cases, PIP operates on a "0", which we consider in more
detail.
In the "0" information VU -> SM and
SM - "VU introduced continuously, ie output register changes
its state to change the data input.
Channel C has a singularity - it is
of two 4-bit registers, which
aggregate can be used as
8-bit register. In addition to the channel C
You can control every bit separately.
Mode of each channel is determined by the register control
word (RUS), which entered the desired
code. As shown in the program RUS
Fig.
Setting and Programming
channels (I / O).
Group A Group B
D7 D6 D5 D4 D3 D2 D1 D0
1 1 / 0 1 / 0 1 / 0 1 / 0
Installing C4 C3 C7 ... C0 ...
regime
A7 ... A0 B7 ... B0
Mode Group A Group B Mode
Mode "0" - 0 0 Mode 0 - 0
Mode 1 - 0 1 Mode 1 "- 1
"2" - 1 x
(1 / 0 - 1-input, 0-O)
Setting / resetting individual bits
Canal St.
D7 D6 D5 D4 D3 D2 D1 D0
0 X X X 0 / 1
Set / reset number of dis-1-mouth
yes channel with permutation
C0 0 0 0 0-dumping
C1 0 0 1
C 2 0 1 0
.. . . .
C7 1 1 1
Thus each channel A and B, and C halves of the channel can
be programmed as on the input and the output. Manage PPI
VV55A possible from BASICa and from native code.
Must be borne in mind that whenever you change modes every
channel, all input and output registers of channels are reset
to "0".
In my opinion - the main advantage of
the use of PPI is that, when
development of the next design of the external
device (programmer, all kinds of measuring units, DAC, ADC,
etc.) do not need to look for free addresses, and buffered data
bus (where it not buffered), etc. And it still leads to a
saving chips, and correspondingly reduces the load on the power
supply.
Literature: A Guide to Digital scheme
motehnike, VI Zubchuk etc.
Below is a wiring diagram VV55A,
because it is done in a PC "Baltic."
+5 V
26
34 1
D0 BB55 A0
to the bus. . 2,3,4,
data. . . 40,39,38
Z80 27. . 37
D7 A7
September 1918
A5 (1935 Z80) A0 B0
8. .
A6 (1936 Z80) A1. .
35. 25
1926 Z80 O RES B7
36 14
O / WR C0
May 15,16,17,
O / RD 13,12,11
June 1910
DOS O / CS C7
7
Address channels
KR580VV55A:
K555ID4 Channel A - # 1F
/ IORQ 1 Channel B - # 3F
(20) O OE1 D0 Channel C - # 5F
February 2000 6 RUS - # 7F
/ WR (22) E2 01
February 13
A0 (1930) D1 03
3
A7 (1937) D2 D1
15 October 1910
/ RD (1921) OG1 11
December 14
/ IORQ (20) OG2 13
This article was prepared specifically for
e-newspaper ECHO. Any questions can be addressed to:
225710, Belarus, Pinsk,
st. Cherneevichskaya, 19
23.08.98
