74377

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.

If only four or less bits are needed, a 74161 may be used instead.

See also: 74161 Latch Implementation

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

• Philips Semiconductors. 74HC377: Octal D-type flip-flop with data enable; positive-edge trigger