<18/54> VDP1 User's Manual / 4.7 Processing Suspended Table Address Register

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VDP1 User's Manual / Chapter 4 System Registers

■ 4.7 Processing interruption table Address register: The Last operation command address register (LOPR) represents the command table address processed at the end of the previous frame. It is a read-only 16-bit register located at address 100012H.
LOPR 100012H (R) bit15 bit14 bit13 bit12 bit11 bit10 bit9 bit8 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 Processing interruption table address / 8H 0 0
Processing interruption table address: bit15 ~ 0
When switching the frame buffer, the value obtained by dividing the address of the command table that fetched the parameters from VRAM to VDP1 by 8H is written to this register.
This register is updated when the frame buffer is switched, so you can know the final processing command table address of the previous frame.
Since the boundary of the command table address is 20HByte, the lower 2 bits of the register are fixed to 00B.
Figure 4.3 Processing interruption and current processing table address

LOPR 100012H (R)	bit15	bit14	bit13	bit12	bit11	bit10	bit9	bit8	bit7	bit6	bit5	bit4	bit3	bit2	bit1	bit0
Processing interruption table address / 8H	0	0

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■ 4.7 Processing interruption table Address register