6502/pill_6502
1
0
Fork 0
mirror of https://github.com/satoshinm/pill_6502.git synced 2024-06-06 16:29:31 +00:00
Code Issues Projects Releases Wiki Activity

Fix ACIA status/control register, they share the same address (0xa000)

Browse Source
This commit is contained in:
Satoshi N. M 2018-01-13 10:49:44 -08:00
parent f1f1a1f8ac
commit 35ec39e13f
1 changed files with 6 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
src/acia6850.c
View File

@ -13,17 +13,15 @@ extern usbd_device *usbd_dev;
// //
#define ACIAControl 0 #define ACIAControl 0
#define ACIAStatus 1 #define ACIAStatus 0
#define ACIAData 2 #define ACIAData 1
// "MC6850 Data Register (R/W) Data can be read when Status.Bit0=1, and written when Status.Bit1=1." // "MC6850 Data Register (R/W) Data can be read when Status.Bit0=1, and written when Status.Bit1=1."
#define RDRF 1 #define RDRF (1 << 0)
#define TDRE 2 #define TDRE (1 << 1)
uint8_t read6850(uint16_t address) { uint8_t read6850(uint16_t address) {
switch(address & 3) { switch(address & 1) {
case ACIAControl:
break;
case ACIAStatus: case ACIAStatus:
return TDRE; // writable return TDRE; // writable
break; break;
@ -38,13 +36,10 @@ uint8_t read6850(uint16_t address) {
} }
void write6850(uint16_t address, uint8_t value) { void write6850(uint16_t address, uint8_t value) {
switch(address & 3) { switch(address & 1) {
case ACIAControl: case ACIAControl:
// TODO: decode baudrate, mode, break control, interrupt // TODO: decode baudrate, mode, break control, interrupt
break; break;
case ACIAStatus:
(void) value;
break;
case ACIAData: { case ACIAData: {
static char buf[1]; static char buf[1];
buf[0] = value; buf[0] = value;