GMSK Packet Data Modem and RF Transceiver
CMX990
Package
Signal
Q1
Description
Pin No.
Name
Type
17
18
19
20
21
22
29
A5
A4
I/P
I/P
I/P
I/P
I/P
I/P
I/P
Register address select logic inputs.
"
"
"
"
"
A3
A2
A1
A0
RDN
Read. An active low logic level input used to
control the reading of data from the modem into
the controlling µC.
30
WRN
I/P
Write. An active low logic level input used to
control the writing of data into the modem from
the controlling µC.
31
32
CSN
I/P
Chip Select. An active low logic level input
used to enable a data read or write operation.
IRQN
O/P
A ‘wire-ORable’ output for connection to the
host Interrupt Request input. This output has a
low impedance pull down to VSS when active
and is high impedance when inactive. An
external pullup resistor is required.
34
35
36
37
38
39
40
41
D7
D6
D5
D4
D3
D2
D1
D0
BI
BI
BI
BI
BI
BI
BI
BI
Tri-state µC interface data line.
"
"
"
"
"
"
"
ã 2004 CML Microsystems Plc
6
D/990/1
CMLMICRO [ CML MICROCIRCUITS ]
