DNT90CA/PA I/O Descriptions
Pin
Name
I/O
Description
1
GND
-
Power supply and signal ground. Connect to the host circuit board ground.
This pin’s default configuration is data activity output. On a base, this signal blinks when a valid packet is
received. On a remote, this signal blinks when a packet is transmitted. On a router, this signal blinks when
a valid upstream packet is received or a downstream packet is transmitted. Alternate pin function is the di-
agnostic serial port output.
ACT
O
(O)
2
3
4
(DIAG_TX)
This pin’s default configuration is data carrier detect output. On a base, this signal is asserted when any
valid packet is received, and is cleared if no packets are heard for the configured router/remote registra-
tion time-out interval. On a router or remote, this signal is asserted when the radio obtains hopping pattern
synchronization, and remains asserted until no beacons are heard for 50 hops. Alternate pin function is
the diagnostic serial port input.
/DCD
(DIAG_RX)
O
(I)
Configurable digital I/O port 0. When configured as an input, an internal pull-up resistor can be selected
and direct interrupt from sleep can be invoked. When configured as an output, the power-on state is
configurable. In sleep mode the pin direction, input pull-up selection or output state are also separately
configurable.
GPIO0
I/O
5
6
RADIO_TXD
RADIO_RXD
O
I
Serial data output from the radio.
Serial data input to the radio.
Default pin function is GPIO4 with the same configuration options as GPIO2. Alternate pin function is
UART/SPI flow control output. The module sets this line low when it is ready to accept data from the host
on the RADIO_RXD or MOSI input. When the line goes high, the host must stop sending data.
GPOI4
(/HOST_CTS)
I/O
(O)
7
Default pin function is GPIO5 with the same configuration options as GPIO2. Alternate pin function is
UART/SPI flow control input. The host sets this line low to allow data to flow from the module on
the RADIO_TXD pin. When the host sets this line high, the module will stop sending data to the host.
GPOI5
(/HOST_RTS)
I/O
(I)
8
9
12-bit DAC 0 output. Full scale output can be referenced to the voltage at pin 25 or the 3.3 V regulated
module bus voltage.
DAC0
O
10
11
GPIO2
GPIO1
I/O
I/O
Configurable digital I/O port 2. Same configuration options as GPIO0.
Configurable digital I/O port 1. Same configuration options as GPIO0.
Default pin function is GPIO3 with the same configuration options as GPIO0. When SPI slave mode oper-
ation is enabled, a logic high on this pin indicates when data is available to be clocked out by the SPI
master.
GPIO3
(DAV)
I/O
(O)
12
13
14
15
16
17
DAC1
VCC
O
I
12-bit DAC 1 output. Same specifications and configuration options as DAC0.
Power supply input, +3.3 to +5.5 Vdc.
GND
-
Power supply and signal ground. Connect to the host circuit board ground.
Power supply and signal ground. Connect to the host circuit board ground.
Active low module hardware reset.
GND
-
/RESET
I
ADC input 0. This pin is a direct ADC input when the ADC is operating in single-ended mode, or the differ-
ential negative input for positive inputs applied to ADC1 or ADC2 when the ADC is operating in differential
mode. Full-scale reading can be referenced to Pin 25 for ratiometric measurements. For absolute mea-
surements, the ADC can use the regulated supply voltage divided by 1.6 (about 2.06 V), or an external
voltage applied to Pin 25. In single-ended mode, ADC measurements are 11-bit unsigned values with full
scale nominally 2.7 V when referenced to a 2.7 V input on Pin 27. In differential mode, ADC measure-
ments are 12-bit signed values.
18
ADC0
I
ADC input 1. Direct input when the ADC is operating in single-ended mode, positive differential input rela-
tive to ADC0 when the ADC is operating in differential mode.
19
ADC1
I
20
21
MISO
MOSI
I/O
I/O
This pin is the SPI master mode input or slave mode output.
This pin is the SPI master mode output or slave mode input.
SPI active low slave select. This pin is an output when the module is operating as a master, and an input
when it is operating as a slave.
22
/SS
I/O
www.RFM.com E-mail: info@rfm.com
© 2012 by RF Monolithics, Inc.
Page 4 of 6
DNT90A - 05/10/12
RFM [ RF MONOLITHICS, INC ]
