HT37B90/HT37B70/HT37B50/HT37B30
Configuration
Option
Pad Name
LCH
I/O
Function
O
O
I
Audio left channel output
¾
¾
¾
¾
¾
SP1, SP0
AUD_IN
VBIAS
Power Amp. output pins
Power Amp. input pin
O
I
Power Amp. voltage bias reference pin.
Schmitt Trigger reset input, active low
RES
OSC1, OSC2 are connected to an external RC network or external crystal,
determined by configuration option, for the internal system clock. If the RC
system clock option is selected, pin OSC2 can be used to measure the sys-
tem clock at 1/8 frequency.
OSC1
OSC2
I
Crystal or RC
O
Note: 1. Each pin on PA can be programmed through a configuration option to have a wake-up function.
2. Individual pins can be selected to have pull-high resistors.
3. Because the two timers are used by MIDI the external timer pin functions are disabled.
HT37B50, HT37B30
Configuration
Pad Name
I/O
Function
Option
VDD
Positive digital power supply
¾
¾
¾
¾
¾
¾
¾
¾
¾
VDD_DAC
VDD_AMP
VDD_ADC
VSS
Positive DAC circuit power supply
Positive power Amp. power supply
Positive ADC circuit power supply
Negative digital power supply, ground
Negative DAC power supply, ground
Negative AMP power supply, ground
Negative ADC power supply, ground
¾
¾
¾
¾
VSS_DAC
VSS_AMP
VSS_ADC
¾
¾
¾
Bidirectional 8-bit input/output port. Each pin can be configured as a wake-up
input by configuration option. Software instructions determine if the pin is a
CMOS output or Schmitt Trigger input. Configuration options determine if all
pins on this port have pull-high resistors. Pins PA5, PA6 and PA7 are
pin-shared with INT, TMR0 and TMR1, respectively.
PA0~PA4
PA5/INT
Pull-high
Wake-up
I/O
PA6/TMR0
PA7/TMR1
Bidirectional 8-bit input/output port. Software instructions determine if the pin
is a CMOS output or Schmitt Trigger input. A configuration option determines
if all pins on this port have pull-high resistors. Pins PB0 ~ PB7 are pin-shared
with AD0 and AD7, respectively.
PB0/AD0~
PB7/AD7
I/O
I/O
Pull-high
Pull-high
Bidirectional 8-bit input/output port. Software instructions determine if the pin
is a CMOS output or Schmitt Trigger input. A configuration option determines
if all pins on this port have pull-high resistors. Pins PC0 ~ PC7 are pin-shared
with K0 and K7, respectively (K0~K7 are CR/F function).
PC0/K0~
PC7/K7
PD0/RCOUT
PD1/RR
Bi-directional 4-bit I/O port. Software instructions determined the CMOS out-
put or Schmitt trigger with a pull-high resistor (determined by pull-high option:
by option). Pins PD0~PD3 are pin-shared with CR/F OSC input pins
RCOUT, RR, RC and CC. RCOUT, RR, RC and CC control pin for CR/F
Function. Pins PD4, PD5, PD6 and PD7 are normal IO.
PD2/RC
I/O
Pull-high
PD3/CC
PD4~PD7
RCH
O
O
O
Audio right channel output
Audio left channel output
Power Amp. output pins
¾
¾
¾
LCH
SP1, SP0
Rev. 1.00
4
June 22, 2017
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
