On 24/08/2021 11:09, Finn Thain wrote:
Reads and writes to the TL and TC registers have no immediate effect on
a running timer, with the exception of a write to TCH. Hence these
mos6522_timer_update() calls are not needed.
Signed-off-by: Finn Thain <fth...@linux-m68k.org>
Perhaps better to flip this description around i.e. mention that the low bytes are
written to a latch and then the full 16-bit value is transferred to the latch/counter
when the high byte is written?
Otherwise I think this looks okay.
---
hw/misc/mos6522.c | 7 -------
1 file changed, 7 deletions(-)
diff --git a/hw/misc/mos6522.c b/hw/misc/mos6522.c
index ff246b5437..1d4a56077e 100644
--- a/hw/misc/mos6522.c
+++ b/hw/misc/mos6522.c
@@ -234,7 +234,6 @@ uint64_t mos6522_read(void *opaque, hwaddr addr, unsigned
size)
val = s->timers[0].latch & 0xff;
break;
case VIA_REG_T1LH:
- /* XXX: check this */
val = (s->timers[0].latch >> 8) & 0xff;
break;
case VIA_REG_T2CL:
@@ -303,8 +302,6 @@ void mos6522_write(void *opaque, hwaddr addr, uint64_t val,
unsigned size)
break;
case VIA_REG_T1CL:
s->timers[0].latch = (s->timers[0].latch & 0xff00) | val;
- mos6522_timer1_update(s, &s->timers[0],
- qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
break;
case VIA_REG_T1CH:
s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8);
@@ -313,14 +310,10 @@ void mos6522_write(void *opaque, hwaddr addr, uint64_t
val, unsigned size)
break;
case VIA_REG_T1LL:
s->timers[0].latch = (s->timers[0].latch & 0xff00) | val;
- mos6522_timer1_update(s, &s->timers[0],
- qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
break;
case VIA_REG_T1LH:
s->timers[0].latch = (s->timers[0].latch & 0xff) | (val << 8);
s->ifr &= ~T1_INT;
- mos6522_timer1_update(s, &s->timers[0],
- qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
break;
case VIA_REG_T2CL:
s->timers[1].latch = (s->timers[1].latch & 0xff00) | val;
ATB,
Mark.
