Mixed Signal PICtail™ Demo Board User’s Guide
DS51523A-page 12
2004 Microchip Technology Inc.
TABLE 2-1:
PICkit™ 1 FLASH STARTER KIT 14-PIN HEADER INTERFACE
PINS
Pin Name
Pin
Number
Pin
Type
Buffer
Type
Description
V
SS
14
—
—
Electrical Ground. Both analog and digital.
V
IN
13
—
—
Power Supply Input. Refer to
Note 2
in
Appendix A
“Schematics and Layouts”
. Do not plug in 9V
supply and connect to PICkit™ 1 Flash Starter Kit.
CS0
12
O
—
SPI™ Chip Select signal for the external ADCs. Do
not populate both the MCP3551 and the MCP3302
as they share the same CS0 signal.
SCK/SCL
11
O
ST
SPI Clock or I
2
C™ Clock Signal. Note that external
weak pull-up R
20
connects this signal to V
DD2
.
SDI/SDA
10
I/O
ST
SPI Data In or I
2
C Data signal (Data Out on ADC).
Note that external weak pull-up R
14
connects this sig-
nal to V
DD2
.
SDO
9
O
—
SPI Data Out Signal (Data In on DAC and ADC)
CS1
8
O
—
SPI Chip Select Signal for the External DACs. Do not
populate both the MCP492X and the MCP482X as
they share the same CS0 signal.
LDAC
7
O
—
Latches the DAC Output When Low. Note the weak
pull-down resistor R
5
if the firmware doesn’t drive the
pin to a desired state.
V
REF_ADC
6
I
—
JP4 selects the V
REF
source to use as the ADC
reference signal. The PICmicro
®
microcontroller on
the PICkit™ 1 Flash Starter Kit may use this for its
internal ADC’s V
REF
.
LED0/TX
5
O
—
Active High Red LED Signal. This I/O also has the
USART’s TX signal multiplexed on it.
LED1/RX
4
I/O
—
Active High Green LED Signal. This I/O also has the
USART’s RX signal multiplexed on it.
SW0
3
I
—
S1’s Switch 1. This pin uses the internal pull-up resis-
tor to determine when the switch is open.
SW1
2
I
—
S1’s Switch 2. This pin uses the internal pull-up resis-
tor to determine when the switch is open.
SW2
1
I
—
S1’s Switch 3. This pin uses the internal pull-up resis-
tor to determine when the switch is open.
Legend:
TTL = TTL compatible input
ST = Schmitt Trigger input with CMOS levels
I = Input
O = Output
