74377: Difference between revisions

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The '''74377'' chip (common variants 74LS377, 74HC377) is an octal D flip-flop, used as a latch in mappers like [[Color Dreams]] and stores eight bits of data.
The [[74377]] chip (common variants 74LS377, 74HC377) is an octal D flip-flop, used as a latch in mappers like [[Color Dreams]] and stores eight bits of data.
== 74377 Pinout ==
== 74377 Pinout ==
    ,---_---.
      .--\/--.
/WE -| 1   20|- Vcc
/WE -| 1 20|- Vcc
Q0 -| 2   19|- Q7
  Q0 -| 2 19|- Q7
D0 -| 3   18|- D7
  D0 -| 3 18|- D7
D1 -| 4   17|- D6
  D1 -| 4 17|- D6
Q1 -| 5   16|- Q6
  Q1 -| 5 16|- Q6
Q2 -| 6   15|- Q5
  Q2 -| 6 15|- Q5
D2 -| 7   14|- D5
  D2 -| 7 14|- D5
D3 -| 8   13|- D4
  D3 -| 8 13|- D4
Q3 -| 9   12|- Q4
  Q3 -| 9 12|- Q4
GND -|10   11|- CLK
GND -|10 11|- CLK
    `-------'
      `------'
== Signal descriptions ==
== Signal descriptions ==
*Vcc: Connect to +5V
*Vcc: Connect to +5V

Revision as of 04:27, 31 January 2013

The 74377 chip (common variants 74LS377, 74HC377) is an octal D flip-flop, used as a latch in mappers like Color Dreams and stores eight bits of data.

74377 Pinout

     .--\/--.
/WE -| 1  20|- Vcc
 Q0 -| 2  19|- Q7
 D0 -| 3  18|- D7
 D1 -| 4  17|- D6
 Q1 -| 5  16|- Q6
 Q2 -| 6  15|- Q5
 D2 -| 7  14|- D5
 D3 -| 8  13|- D4
 Q3 -| 9  12|- Q4
GND -|10  11|- CLK
     `------'

Signal descriptions

  • Vcc: Connect to +5V
  • GND:
  • CLK: Load clock
  • /WE: Write enable
  • D0-7: Inputs, connected to CPU D0-D7
  • Q0-7: Outputs, connected to PRG and CHR ROM address lines

D0-7 are copied to Q0-7 when CLK rises (0 to 1) while /WE is low.

References