Nintendo DMG-01 - Game Boy Console Manual page 53

TM
Game Boy CPU Manual
Bit 6 - LYC=LY Coincidence (Selectable)
Bit 5 - Mode 10
Bit 4 - Mode 01
Bit 3 - Mode 00
Bit 2 - Coincidence Flag
Bit 1-0 - Mode Flag
STAT shows the current status of the LCD controller.
Mode 00: When the flag is 00 it is the H-Blank
Mode 01: When the flag is 01 it is the V-Blank
Mode 10: When the flag is 10 then the OAM is being
Mode 11: When the flag is 11 both the OAM and
The following are typical when the display is
enabled:
by DP
0: Non Selection
1: Selection
0: LYC not equal to LCDC LY
1: LYC = LCDC LY
00: During H-Blank
01: During V-Blank
10: During Searching OAM-RAM
11: During Transfering Data to
period and the CPU can access the display
RAM ($8000-$9FFF).
period and the CPU can access the display
RAM ($8000-$9FFF).
used ($FE00-$FE9F). The CPU cannot access
the OAM during this period
display RAM are being used. The CPU cannot
access either during this period.
LCD Driver
2.13.1. I/O Registers
Page 53