Motorola ASTRO Digital Spectra, Detailed Service Manual, Page: 422 / 442

September 5, 2008 6881076C25-E
A-2 Secure Modules: Circuit Description
A.2 Circuit Description
The secure module operates from three power supplies (, SW_B+, and KG_BACKUP).
The SW_B+ is turned on and off by the radio’s on/off switch. The provides power to the
secure module as long as the radio battery is in place.
Key variables are loaded into the secure module through connector P1, pin 15. Up to 16 keys
(depending on the type of encryption module) can be stored in the module at a time. The key can be
infinite key retention or 3 day key retention, depending on how the code plug is setup.
The radio’s host processor communicates with the secure module on the Serial Peripheral Interface
(SPI) bus. The host processor is the master on this bus, while the secure module is a slave on the
bus. The SPI bus consists of five signal lines. Refer to
Table A-1 for signal information. A
communications failure between the host processor and the secure module will be indicated as an
“ERROR 09/10” message on the radio display.
A.3 Troubleshooting Secure Operations
Refer to the ASTRO Digital Spectra and Digital Spectra Plus Mobile Radios Basic Service Manual
(6881076C20) for disassembly and reassembly information. A key-variable loader (KVL) and
oscilloscope are needed to troubleshoot the secure module.
NOTE: The secure module itself is not serviceable. If the secure module is found to be defective, it
must be replaced.
A.3.1 Error 09/10, Error 09/90
The ASTRO Digital Spectra Mobile Radio automatically performs a self test on every power-up.
Should the radio fail the self tests, the display will show “ERROR 09/10” or “ERROR 09/90”
accompanied by a short beep. If the display shows “ERROR 09/10” or “ERROR 09/90
, ” the radio
failed the secure power-up tests and the host microcontroller was unable to communicate with the
secure module via the SPI bus. Turn the radio off and back on. If the radio still does not pass the self
tests, then a problem exists with the secure operations of the radio.
Troubleshooting information for “ERROR 09/10” is found in Troubleshooting Chart C.17, "09/10,
Secure Hardware Failure," on page 5-13 . For “ERROR 09/90 , ” see Troubleshooting Chart C.18,
"09/90, Secure Hardware Failure," on page 5-13 .
A.3.2 Keyload
When the keyloading cable is attached to the ASTRO Digital Spectra Mobile Radio and
“KEYLOADING” is not displayed on the ASTRO Digital Spectra Mobile Radio display, then the radio
has not gone into KEYLOAD mode. For troubleshooting a “KEYLOAD” failure, refer to
Troubleshooting
Chart C.21, "Key Load Fail," on page 5-16 .
NOTE: ASTRO Digital Spectra Mobile Radios need a keyloader that has the ability to keyload a
ASTRO Digital Spectra Mobile Radio. The keyloader must be either a KVL-3000 or later
model key-variable loader.