Service manual

ManualsBrandsE.F. Johnson Company ManualsGadgetsLTR-Net 7243

CIRCUIT DESCRIPTION

4-7

November 2001

Part No. 001-7240-001

64 - - External pull-up -

65 BEEP Output Audio beep tone -

66 - - - -

67 - - - -

68 - - - -

69 - - - -

70 - - - -

71 P_HOLD - - -

72 FWE Input Flash memory Write Enable -

73 RESET Input Reset pulse input -

74 - - External pull-up -

75 L5V - - -

76 Vcc - L5V -

77 X-TAL Input System clock connection terminal -

78 EX-TAL Input System clock connection terminal -

79 Vss - Ground -

80 - - - -

81 Vcc - L5V -

82 TMUT - Not used -

83 T5C Output T5V supply control signal High

84 DPTT Output Delayed PTT signal Low

85 R5C Output R5V supply control signal High

86 - - - -

87 - - - -

88 NPSPAC Output Controls NPSPAC channel audio level High

89 MSO Output Serial data output -

90 MSI Input Serial data input -

91 SER_CLOCK Output Serial data clock -

92 - - - -

93 Avcc - L5V -

94 Vref - L5V -

95 BATT(VCC) Input Low battery voltage detection -

96 RSSI Input RSSI (Receive Signal Strength Indicator) -

97 L5V - L5V -

98 Ground - Ground -

99 - - External pull-up -

100 - - External pull-up -

101 - - External pull-up -

102 VVC_LVL - - -

103 AVss - Ground -

104 Vss - Ground -

105 TEST Output Bypass transmit data filter High

106 TXPREC Output Subaudible signaling tone/damp signal output -

Table 4-1 Microprocessor U208 Pin Descriptions (Continued)

Pin No. Port Name In/Out Descriptions Active