Introduce a new next_rtc_cmd_is_write() function to determine if an rtc command
is a read or write, and start by using it to avoid shifting the rtc input value
if a rtc read command is executed.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
---
hw/m68k/next-cube.c | 138 ++++++++++++++++++++++++--------------------
1 file changed, 74 insertions(+), 64 deletions(-)
diff --git a/hw/m68k/next-cube.c b/hw/m68k/next-cube.c
index bb375b63ca..4aed80c9fe 100644
--- a/hw/m68k/next-cube.c
+++ b/hw/m68k/next-cube.c
@@ -165,6 +165,12 @@ static void next_scr2_led_update(NeXTPC *s)
}
}
+static bool next_rtc_cmd_is_write(uint8_t cmd)
+{
+ return (cmd >= 0x80 && cmd <= 0x9f) ||
+ (cmd == 0xb1);
+}
+
static void next_scr2_rtc_update(NeXTPC *s)
{
uint8_t old_scr2, scr2_2;
@@ -186,76 +192,80 @@ static void next_scr2_rtc_update(NeXTPC *s)
((scr2_2 & SCR2_RTDATA) ? 1 : 0);
}
if (rtc->phase >= 8 && rtc->phase < 16) {
- rtc->value = (rtc->value << 1) |
- ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
-
- /* if we read RAM register, output RT_DATA bit */
- if (rtc->command <= 0x1F) {
- scr2_2 = scr2_2 & (~SCR2_RTDATA);
- if (rtc->ram[rtc->command] & (0x80 >> (rtc->phase - 8))) {
- scr2_2 |= SCR2_RTDATA;
- }
-
- rtc->retval = (rtc->retval << 1) |
- ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
- }
- /* read the status 0x30 */
- if (rtc->command == 0x30) {
- scr2_2 = scr2_2 & (~SCR2_RTDATA);
- /* for now status = 0x98 (new rtc + FTU) */
- if (rtc->status & (0x80 >> (rtc->phase - 8))) {
- scr2_2 |= SCR2_RTDATA;
+ if (next_rtc_cmd_is_write(rtc->command)) {
+ /* Shift in value to write */
+ rtc->value = (rtc->value << 1) |
+ ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
+ } else {
+ /* Shift out value to read */
+
+ /* if we read RAM register, output RT_DATA bit */
+ if (rtc->command <= 0x1F) {
+ scr2_2 = scr2_2 & (~SCR2_RTDATA);
+ if (rtc->ram[rtc->command] &
+ (0x80 >> (rtc->phase - 8))) {
+ scr2_2 |= SCR2_RTDATA;
+ }
+
+ rtc->retval = (rtc->retval << 1) |
+ ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
}
-
- rtc->retval = (rtc->retval << 1) |
- ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
- }
- /* read the status 0x31 */
- if (rtc->command == 0x31) {
- scr2_2 = scr2_2 & (~SCR2_RTDATA);
- if (rtc->control & (0x80 >> (rtc->phase - 8))) {
- scr2_2 |= SCR2_RTDATA;
+ /* read the status 0x30 */
+ if (rtc->command == 0x30) {
+ scr2_2 = scr2_2 & (~SCR2_RTDATA);
+ /* for now status = 0x98 (new rtc + FTU) */
+ if (rtc->status & (0x80 >> (rtc->phase - 8))) {
+ scr2_2 |= SCR2_RTDATA;
+ }
+
+ rtc->retval = (rtc->retval << 1) |
+ ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
}
- rtc->retval = (rtc->retval << 1) |
- ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
- }
-
- if ((rtc->command >= 0x20) && (rtc->command <= 0x2F)) {
- scr2_2 = scr2_2 & (~SCR2_RTDATA);
- /* for now 0x00 */
- time_t time_h = time(NULL);
- struct tm *info = localtime(&time_h);
- int ret = 0;
-
- switch (rtc->command) {
- case 0x20:
- ret = SCR2_TOBCD(info->tm_sec);
- break;
- case 0x21:
- ret = SCR2_TOBCD(info->tm_min);
- break;
- case 0x22:
- ret = SCR2_TOBCD(info->tm_hour);
- break;
- case 0x24:
- ret = SCR2_TOBCD(info->tm_mday);
- break;
- case 0x25:
- ret = SCR2_TOBCD((info->tm_mon + 1));
- break;
- case 0x26:
- ret = SCR2_TOBCD((info->tm_year - 100));
- break;
-
+ /* read the status 0x31 */
+ if (rtc->command == 0x31) {
+ scr2_2 = scr2_2 & (~SCR2_RTDATA);
+ if (rtc->control & (0x80 >> (rtc->phase - 8))) {
+ scr2_2 |= SCR2_RTDATA;
+ }
+ rtc->retval = (rtc->retval << 1) |
+ ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
}
- if (ret & (0x80 >> (rtc->phase - 8))) {
- scr2_2 |= SCR2_RTDATA;
+ if ((rtc->command >= 0x20) && (rtc->command <= 0x2F)) {
+ scr2_2 = scr2_2 & (~SCR2_RTDATA);
+ /* for now 0x00 */
+ time_t time_h = time(NULL);
+ struct tm *info = localtime(&time_h);
+ int ret = 0;
+
+ switch (rtc->command) {
+ case 0x20:
+ ret = SCR2_TOBCD(info->tm_sec);
+ break;
+ case 0x21:
+ ret = SCR2_TOBCD(info->tm_min);
+ break;
+ case 0x22:
+ ret = SCR2_TOBCD(info->tm_hour);
+ break;
+ case 0x24:
+ ret = SCR2_TOBCD(info->tm_mday);
+ break;
+ case 0x25:
+ ret = SCR2_TOBCD((info->tm_mon + 1));
+ break;
+ case 0x26:
+ ret = SCR2_TOBCD((info->tm_year - 100));
+ break;
+ }
+
+ if (ret & (0x80 >> (rtc->phase - 8))) {
+ scr2_2 |= SCR2_RTDATA;
+ }
+ rtc->retval = (rtc->retval << 1) |
+ ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
}
- rtc->retval = (rtc->retval << 1) |
- ((scr2_2 & SCR2_RTDATA) ? 1 : 0);
}
-
}
rtc->phase++;
--
2.39.5
