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[Core/CD] improved accuracy of CDC transfer to Main-CPU (resp. Sub-CPU) when destination is set to Sub-CPU (resp. Main-CPU) (verified on real hardware, cf. Krikzz's mcd-verificator)

This commit is contained in:
ekeeke 2024-01-19 00:01:02 +01:00
parent b35a602bb3
commit 16589b558f
4 changed files with 11 additions and 8 deletions
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8
core/cd_hw/cdc.c
View File

@ -2,7 +2,7 @@
* Genesis Plus
* CD data controller (LC8951x compatible)
*
* Copyright (C) 2012-2023 Eke-Eke (Genesis Plus GX)
* Copyright (C) 2012-2024 Eke-Eke (Genesis Plus GX)
*
* Redistribution and use of this code or any derivative works are permitted
* provided that the following conditions are met:
@ -769,13 +769,13 @@ unsigned char cdc_reg_r(void)
return data;
}
unsigned short cdc_host_r(void)
unsigned short cdc_host_r(uint8 cpu_access)
{
/* read CDC buffered data (gate-array register $08) */
uint16 data = scd.regs[0x08>>1].w;
/* check if host data transfer is enabled */
if (scd.regs[0x04>>1].byte.h & 0x40)
/* check if host data transfer is started for selected CPU */
if ((scd.regs[0x04>>1].byte.h & 0x47) == cpu_access)
{
/* check if EDT bit (gate-array register $04) is set (host data transfer is finished) */
if (scd.regs[0x04>>1].byte.h & 0x80)

7
core/cd_hw/cdc.h
View File

@ -2,7 +2,7 @@
* Genesis Plus
* CD data controller (LC8951x compatible)
*
* Copyright (C) 2012-2023 Eke-Eke (Genesis Plus GX)
* Copyright (C) 2012-2024 Eke-Eke (Genesis Plus GX)
*
* Redistribution and use of this code or any derivative works are permitted
* provided that the following conditions are met:
@ -40,6 +40,9 @@
#define cdc scd.cdc_hw
#define CDC_MAIN_CPU_ACCESS 0x42
#define CDC_SUB_CPU_ACCESS 0x43
/* CDC hardware */
typedef struct
{
@ -67,6 +70,6 @@ extern void cdc_dma_update(void);
extern void cdc_decoder_update(uint32 header);
extern void cdc_reg_w(unsigned char data);
extern unsigned char cdc_reg_r(void);
extern unsigned short cdc_host_r(void);
extern unsigned short cdc_host_r(uint8 cpu_access);
#endif

2
core/cd_hw/scd.c
View File

@ -680,7 +680,7 @@ static unsigned int scd_read_word(unsigned int address)
/* CDC host data (word access only ?) */
if (address == 0x08)
{
return cdc_host_r();
return cdc_host_r(CDC_SUB_CPU_ACCESS);
}
/* LED & RESET status */

2
core/mem68k.c
View File

@ -537,7 +537,7 @@ unsigned int ctrl_io_read_word(unsigned int address)
{
s68k_sync();
}
return cdc_host_r();
return cdc_host_r(CDC_MAIN_CPU_ACCESS);
}
/* H-INT vector (word access only ?) */