Datasheet

7
AT8xC51SND1C
4109E–8051–06/03
Table 3. Timer 0 and Timer 1 Signal Description
Table 4. Audio Interface Signal Description
Table 5. USB Controller Signal Description
Signal
Name Type Description
Alternate
Function
INT0
I
Timer 0 Gate Input
INT0
serves as external run control for timer 0, when selected by
GATE0 bit in TCON register.
External Interrupt 0
INT0
input sets IE0 in the TCON register. If bit IT0 in this register is set,
bit IE0 is set by a falling edge on INT0#. If bit IT0 is cleared, bit IE0 is
set by a low level on INT0#.
P3.2
INT1
I
Timer 1 Gate Input
INT1
serves as external run control for timer 1, when selected by
GATE1 bit in TCON register.
External Interrupt 1
INT1
input sets IE1 in the TCON register. If bit IT1 in this register is set,
bit IE1 is set by a falling edge on INT1#. If bit IT1 is cleared, bit IE1 is
set by a low level on INT1#.
P3.3
T0 I
Timer 0 External Clock Input
When timer 0 operates as a counter, a falling edge on the T0 pin
increments the count.
P3.4
T1 I
Timer 1 External Clock Input
When timer 1 operates as a counter, a falling edge on the T1 pin
increments the count.
P3.5
Signal
Name Type Description
Alternate
Function
DCLK O DAC Data Bit Clock -
DOUT O DAC Audio Data -
DSEL O
DAC Channel Select Signal
DSEL is the sample rate clock output.
-
SCLK O
DAC System Clock
SCLK is the oversampling clock synchronized to the digital audio data
(DOUT) and the channel selection signal (DSEL).
-
Signal
Name Type Description
Alternate
Function
D+ I/O
USB Positive Data Upstream Port
This pin requires an external 1.5 KΩ pull-up to V
DD
for full speed
operation.
-
D- I/O USB Negative Data Upstream Port -