The MMC4 mapper, used in Fire Emblem and Family War, is similar to the MMC2 used in Punch-Out!! with the following changes: banks are 16 KB instead of 8 KB, and $0000-$0FFF now has its own latch ("latch 0"), instead of sharing it with $1000-$1FFF ("latch 1").

76543210  $A000-$AFFF
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++++++++- Select 16 KB bank in CPU $8000-$BFFF
          ($C000-$FFFF is hardwired to last bank)

76543210  $D000-$DFFF
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++++++++- Select 4 KB bank in PPU $0000-$0FFF
          to be used when latch 0 is set to 'D'

76543210  $E000-$EFFF
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++++++++- Select 4 KB bank in PPU $0000-$0FFF
          to be used when latch 0 is set to 'E'

76543210  $D000-$DFFF
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++++++++- Select 4 KB bank in PPU $1000-$1FFF
          to be used when latch 1 is set to 'D'

76543210  $E000-$EFFF
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++++++++- Select 4 KB bank in PPU $1000-$1FFF
          to be used when latch 1 is set to 'E'

76543210  $F000-$FFFF
       |
       +- 0: Vertical mirroring;
          1: Horizontal mirroring

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