Nokia 9000i Service Manual page 52

RAE/RAK–1N
Baseband
– CTRLU – ACCESSORIES
MBUS is used to control external accessories. This interface can also be
used for factory testing and maintenance purposes.
There are also some control and indication signals for the accessories:
JCONN is used to indicate that junction box is connected. JCONN is
actually the DC–level of the EXTMIC signal. Phone can also enter
minimum mode when MBUS is connected to EXTMIC line.
Main components
– Hitachi H8/538
H8/538 is a CMOS microcontroller unit (MCU) which includes a static CPU
core and on–chip supporting modules with 16–bit architecture. The data
bus to outside world is 16 bits wide.
– SCL ASIC
– MCU address decoding and memory chip select generation
– FLASH and system ASIC address mapping
– MBUS interface
– MBUS/RBUS activity detection
– MCU clock division from 26 MHz to 13 MHz
– 512k*16bit FLASH memory
– two 512Kx8 FLASH chips
– 65 ns maximum read access time
– contains the main program code for the MCU; part of the DSP pro-
gram code also located on FLASH
– 64k*16bit SRAM memory
– two 64Kx8 SRAM chips
– 65 ns maximum read access time
– 8k*8bit EEPROM memory
– 150 ns maximum read access time
– contains user defined information
PWRU
Introduction
The power block creates the supply voltages for the baseband block and
contains the charging switch and its control electronics.
Technical description
Table 29. External Signals and Connections, Inputs
Signal Name
XPWRON Power on switch
XPWROFF PSL+ watchdog updating; power off control
VBATT Battery voltage
Page 2–26
Signal description
After Sales
Technical Documentation
From
B2B Conn
CTRLU
Battery conn
Original, 08/96