Mcu Digital; Real Time Clock; Figure 3-2. Controller Block Diagram - Motorola HT Series Service Manual

3-2
To Synthesizer
16.8 / 17.0 MHz
Reference Clock
from Synthesizer
Recovered Audio
Squelch
To RF Board
3.1.1

MCU Digital

The digital portion of the controller consists of a microcontroller and associated EEPROM, RAM, and
ROM memories. Combinations of different size RAM and ROM are available to support various
application software. RAM supports 8KB and 32KB sizes. ROM supports 128KB, 256KB, and 512KB
sizes. Table 3-1
PROTOCOL
AA,DU
AA,DU
CK, GB, GE, FC
3.1.2

Real Time Clock

Radios with displays support a real time clock (RTC) module for purposes of message time stamping
and time keeping. The RTC module resides in the microcontroller. The clock uses a back-up lithium-
ion battery for operating power when the primary battery is removed.
Mod Out
3.3V
Regulator
(Vdda)
SPI
MCU Digital
3.3V
Regulator
(Vddd)

Figure 3-2. Controller Block Diagram

lists the ROM, RAM and EEPROM requirements for different radios.
Table 3-1. Radio Memory Requirements
FEATURE LEVEL
2 or 3
6
-
Audio/Signalling
Audio Power
ASFIC
Amplifier/Filter
CLK
Microcontroller
EEPROM
ROM RAM
ROM (KB)
128
128
512
Keypad: Controller Board
External
Microphone
Internal
Microphone
SCI to Side
Connector
EXT RAM EEPROM
(KB) (KB)
- 8
- 16
32 16
External
Speaker
Internal
Speaker