Encryption Voltages; Table 3-13. Integrated Circuits Voltages - Motorola ASTRO Digital XTL 5000 Detailed Service Manual

3-66
The various voltages used by the ICs on the main board are shown in
Integrated Circuit UNSW5V
Patriot
Microprocessor
Flash
SRAM
A/D
D/A
Modulation D/A
Urchin
RS-232 XCVR
USB XCVR
Audio PA
CODEC
Amplifiers, EPOTs
555 Timer U0506-4
SB9600 MUX
Volume Pot
32K Crystal
Modulation MUX
Power Control
Keyed 9.1 V Switch
3.8.3

Encryption Voltages

The secure interface board produces two voltages sourced by A+ and SW_B+ through J0501, pins
10 and 9, that are used by the encryption module: UNSW_B+_ENC (7 V) and SW_B+_ENC (7 V).
The constant 7 V is generated using U800, Q802, and Q803 and is fed to J0701. At the secure
interface board, the 7 V provides continuous unswitched voltage when the vehicular battery is
connected to the radio and is also switched to provide SWB+ to the encryption module. A 5-V
storage circuit, C810 (0.47-farad capacitor), provides +5 Vdc to the encryption module via J0701, pin
12, to hold encryption keys for a period of three days with no A+ voltage present. The 5 V and 2.85 V
controller supplies are used to provide logic translation between the legacy keyloader data (5 V) and
the universal crypto module (UCM) (3 V). The secure interface board also supplies the UCM chip-
select logic line and the other control lines, clocks, and other components, to the main board
microprocessor.
May 25, 2005

Table 3-13. Integrated Circuits Voltages

SW 5V A+ 3.0 V
U0953-28
U0959-4
U0305-16
U0204-7
U606-16
U0206-7
Theory of Operation: Controller Section
Table 3-13.
9.3 V_T
2.85 V 1.85 V
X
U100 U100
U102
U103
U0900-3
FL0900-4
U0901
U0304-7
U200-6
U0201-4
U0202-3
Y0100-5
U0902-16
U0956-4
U0957-4
U0960-4
Q0952
1.55 V
U100
6881096C74-B