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author Couriersud <couriersud@users.noreply.github.com>2008-11-03 01:16:39 +0000
committer Couriersud <couriersud@users.noreply.github.com>2008-11-03 01:16:39 +0000
commit17b6c56de9cfd441ed8b09fbd74fb55573596311 (patch)
tree5f2baa5e8cbae6f30688b85634c6183294aa8424 /src/emu/machine/74123.c
parentb29e06704bc7b1bb3c2e7ef9111c1bea6f132f49 (diff)
74123 Fixes:
* Clear behaviour to follow datasheet. * Avoid recursive calls when setting a/b/clear lines from callback
Diffstat (limited to 'src/emu/machine/74123.c')
-rw-r--r--src/emu/machine/74123.c24
1 files changed, 18 insertions, 6 deletions
diff --git a/src/emu/machine/74123.c b/src/emu/machine/74123.c
index 1439eeb6373..a2bc6878094 100644
--- a/src/emu/machine/74123.c
+++ b/src/emu/machine/74123.c
@@ -71,12 +71,21 @@ static int timer_running(ttl74123_t *chip)
}
+static TIMER_CALLBACK( output_callback )
+{
+ const device_config *device = ptr;
+ ttl74123_t *chip = get_safe_token(device);
+
+ chip->intf->output_changed_cb(device, 0, param);
+}
+
+
static void set_output(const device_config *device)
{
ttl74123_t *chip = get_safe_token(device);
int output = timer_running(chip);
- chip->intf->output_changed_cb(device, 0, output);
+ timer_set( attotime_zero, (void *) device, output, output_callback );
if (LOG) logerror("74123 %s: Output: %d\n", device->tag, output);
}
@@ -85,8 +94,10 @@ static void set_output(const device_config *device)
static TIMER_CALLBACK( clear_callback )
{
const device_config *device = ptr;
+ ttl74123_t *chip = get_safe_token(device);
+ int output = timer_running(chip);
- set_output(device);
+ chip->intf->output_changed_cb(device, 0, output);
}
@@ -154,14 +165,15 @@ WRITE8_DEVICE_HANDLER( ttl74123_clear_w )
{
ttl74123_t *chip = get_safe_token(device);
- /* clear the output if A=LO, B=HI and falling edge on clear */
- if (!data && chip->clear && chip->b && !chip->a && !chip->clear)
+ /* start/regtrigger pulse if B=HI and A=LO and rising edge on clear */
+ if (data && !chip->a && chip->b && !chip->clear)
+ start_pulse(device);
+ else if (!data) /* clear the output */
{
timer_adjust_oneshot(chip->timer, attotime_zero, 0);
if (LOG) logerror("74123 #%s: Cleared\n", device->tag );
}
-
chip->clear = data;
}
@@ -185,7 +197,7 @@ static DEVICE_START( ttl74123 )
chip->intf = device->static_config;
assert_always(chip->intf, "No interface specified");
- assert_always((chip->intf->connection_type == TTL74123_GROUNDED) && (chip->intf->cap >= CAP_U(0.01)), "Only capacitors >= 0.01uF supported for GROUNDED type");
+ assert_always((chip->intf->connection_type != TTL74123_GROUNDED) || (chip->intf->cap >= CAP_U(0.01)), "Only capacitors >= 0.01uF supported for GROUNDED type");
assert_always(chip->intf->cap >= CAP_P(1000), "Only capacitors >= 1000pF supported ");
chip->timer = timer_alloc(clear_callback, (void *) device);