Table 3-2. Transceiver - Vocon Interface Signals - Motorola ASTRO XTSTM 4000 Detailed Service Manual

Theory of Operation: Transceiver Section
3.1.1.2 Transceiver and VOCON Section Interface
The transceiver and VOCON section interface is a digital interface carrying DC power, control, and
data between the XCVR and VOCON sections.
Table 3-2 lists the interface connections, their signals, and functions. SPI refers to serial peripheral
interface, which is the control bus from the microprocessor. SSI is the serial synchronous interface
bus for data to and from the DSP. There is a RX SSI bus for demodulated data from the receiver and
a TX SSI bus for modulation data to the transmitter.
VOCON Signal
XRFUNSWB+1
XLOCK
XTX_DATA
XSSI_CLK
XSSI_FSYNC
X16.8MHz
XSWB+2
XTX_SSFS
XTS_SSCK
XRX_DATA
XABACUS3_CS
XRF_VSW1
XRF_SCKA
XRF_BAT_STAT
XRF_MOSIA
XFN_PC_SEL
XRF_POR
3.1.1.3 Antenna Contact M1704
Antenna contact M1704 is a surface mount, leaf spring contact which comes into contact with the
antenna pin on the radio chassis assembly. This contact routes the RF power to/from the transceiver
to the antenna.
6871620L01-C
Table 3-2. Transceiver – VOCON Interface Signals
XCVR XCVR
Signal I/O
FUB+ O
LOCK O
TXTD O
RXCK O
RXFS O
F168 O
XCVR_SWB+ I
TXFS I
TXCK I
RXDO O
ABCS I
VSW1 I
SPCK I
DATA O
MOSI I/O
USEL I
RSTL I/O
Type Description
dc Fused B+ to VOCON
status FGU lock detect
ssi TX SSI data
ssi RX SSI clock
ssi RX SSI frame sync
RF 16.8 MHz reference clock
dc Switch control
ssi TX SSI frame sync
ssi TX SSI clock
ssi RX SSI data
ssi SPI Abacus chip select
dc Regulated 3.8 V
spi SPI clock
dc Battery status
spi SPI data I/O
spi SPI universal chip select
control asynchronous reset, active low
3-3
May 28, 2008