Sgb Register Summary - Nintendo GAME BOY Programming Manual

Game Boy Programming Manual

4.3 SGB Register Summary

The following registers can be used to perform functions such as resetting the SGB CPU from a
program transferred to Super NES W-RAM and receiving and passing data to a DMG program.
Register File Status
6002h
[RFS] (RD)
DMG Reset Register
6003h
[DRR] (WR)
Controller Register1
6004h
[CR1] (WR)
Register File
7000h
[RF - RF ]
0 F
The SGB CPU can be reset using DRR.
Using RF
- RF
0 F
the Super NES program.
is a register used by the original SGB system program for writing keypad data from controller 1.
CR1
The Super NES program can use the controller-reading routine of the DMG program to receive data
written to this register.
700Fh
- (RD)
and allows data sent to the register file by the DMG program to be received by
RFS
Reads the status of the register file
Resets the SGB CPU
-- 0 0
0: Reset
1: Cancel
Writes data from Controller 1
ST SE B A
Data read at P15
Register file for communication
* The RFS flag (6002h) is cleared to 0 by the
reading of 7000h.
184
1:Ready
mid-transfer or read
0:
finished
-- -- 0 1
D U L R
Data read at P14