Vocon Board Signals; Table 3-2. Vocon Board Address Bus (A) Pinouts - Motorola ASTRO Digital Spectra Plus Detailed Service Manual

Theory of Operation: ASTRO Spectra VOCON Board
During this process, the MCU does power diagnostics. These diagnostics include verifying the MCU
system RAM, and verifying the data stored in the internal EEPROM, external EEPROM, and FLASH
ROMs. The MCU queries the DSP for proper status and the results of DSP self tests. The DSP self
tests include testing the system RAM, verifying the program code in ROM U404, and returning the
ADSIC configuration register checksum. Any failures cause the appropriate error codes to be sent to
the display. If everything is OK, the appropriate radio state is configured and the unit waits for user
input.
On power-down, the user opens the radio on/off switch, removing the B+_SENSE signal from the
controller board. This does not immediately remove power, as the MCU holds this line active through
B+_CNTL. The MCU then saves pertinent radio status data to the external EEPROM. Once this is
done, B+_CNTL is released, shutting off SW_B+ at Q106 and shutting down the 5-Vdc regulator
U709. When the regulator slumps to about 4.7 Vdc, supervisory IC U726 activates a system reset to
the SLIC, which in turn resets the MCU.

3.3.14 VOCON Board Signals

Due to the nature of the schematic-generating program, signal names must be different when they
are not directly connected to the same point. The following tables provide a cross-reference to the
various pinouts for the same functional signal.
Bus
A0
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
A13
A14
A15
6881076C25-E

Table 3-2. VOCON Board Address Bus (A) Pinouts

U402 U403 U404
A4 A4 20
B4 B4 19
A3 A3 18
B3 B3 17
A2 A2 16
B2 B2 15
J6 J6 14
K7 K7 13
J7 J7 3
K8 K8 2
B8 B8 31
A8 A8 1
B7 B7 12
J3 – 4
– – 5
K3 K3 11
U405 U406 U414
C2 E9 A4
D3 E10 B4
D2 E8 A3
E2 – B3
D4 – A2
B1 – B2
E3 – J6
F1 – K7
F2 – J7
F3 – K8
G1 – B8
J2 – A8
K1 – B7
H3 D9 –
G2 B9 –
H2 D10 J3
3-29
U415
–
–
–
–
–
–
–
–
–
–
–
–
–
2
1
–
September 5, 2008