Bdisp DDRegisterSelect

Synopsis

Header: fxcg/display.h
Syscall index: 0x01A2
Function signature: void Bdisp_DDRegisterSelect(int registerno)

Probably responsible for setting a register on the LCD controller (0xB4000000).

Comments

This syscall clears bit 4 of 0xA405013C.b, writes P1 (r4) to 0xB4000000 and finally sets bit 4 of 0xA405013C.b again. It looks as if bit 4 controls the LCD-driver's RS-bit; refer to the R61509-manual for more information.

After every write to 0xA405013C or 0xB4000000, the SH-4A processor instruction SYNCO is performed.