Echo #05 31 августа 1998

Железо

Iron - Programmable parallel interface KR580VV55A.

        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



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                                  23.08.98