Motorola APX 2000 Detailed Service Manual

Theory of Operation: Controller 3-51
3.2.7 Encryption
The encryption circuitry is placed on the keypad board and interfaces to the main board through the
J2301-P2001 connector. The encryption circuitry is designed to digitally encrypt and decrypt voice
and ASTRO data in the APX 2000/ APX 4000 radio. The Motorola Advanced Crypto Engine (MACE)
IC is the main component in the encryption design, and has some discrete support circuitry along
with the interfaces to the main board IC's (CPLD, OMAP, and Audio CODEC).
NOTE: The MACE IC is NOT serviceable. The information contained in this section is only intended
to help determine whether a problem is due to the MACE IC or the radio itself.
Figure 3-39 below shows the Encryption architecture for the APX 2000/ APX 4000 radio.
Figure 3-39. APX 2000/ APX 4000 Encryption Architecture
As shown in Figure 3-39 above, the encryption design consists of 5 blocks:
• MACE IC
• Key Loading
• Key Retention
•Tamper
• Key Zeroize.
MACE
(Secure IC)
OMAP
AUDIO
CODEC
SSI
SSI
Key
Zeroize
Tamper
Key
Fail
CPLD
CLK SSI GPIO
Key
Retention

Motorola APX 2000 Specifications

General

Brand	Motorola
Model	APX 2000
Category	Two-Way Radio
Language	English