Motorola HT1250-LS+ - Controller; MCU Digital; Figure 3-3. Controller Block Diagram; Table 3-2. Radio Memory Requirements

Theory of Operation 3-3
3.4 Controller
The controller is the central interface between the various radio functions. It is separated into MCU
digital and audio/signalling functions as shown in Figure 3-3.
Figure 3-3. Controller Block Diagram
3.4.1 MCU Digital
The digital portion of the controller consists of a microcontroller (U409) and associated EEPROM, S-
RAM, and Flash ROM memories. The following memory IC's are used in all 200 MHz and 700 MHz
models unless indicated otherwise in the parts lists:
Table 3-2. Radio Memory Requirements
Reference No. Description Type Size
U405 Static RAM SRM2B256 32K x 8
U406 Flash ROM AT 49H LV0 10 128K x 8
U407 Serial EEPROM X25128-2.7 16K x 8
External
Microphone
Internal
Microphone
External
Speaker
Internal
Speaker
SCI to Side
Connector
Audio/Signalling
To Synthesizer
Mod Out
16.8 / 17.0 MHz
Reference Clock
from Synthesizer
Recovered Audio
Squelch
SPI
MCU Digital
RAM
EEPROM
ROM
Microcontroller
ASFIC
3.3V
Regulator
(Vdda)
3.3V
Regulator
(Vddd)
Audio Power
Amplifier/Filter
CLK
To RF Board