ETS2228 Maintenance Manual
All right reserved
Page 6, Total 43
board is Terminal Communication Process Unit (TCPU) and Phone Interface Process Unit (PIPU). The
hardware architecture of FWT is shown in Figure 1.
The TCPU is the core of an FWT, including a radio frequency (RF) receiving and transmitting unit,
a central processing unit and a power module.
The PIPU and the TCPU are connected through a 72-pin weld-pads (72 weld-pads locates around
the TCPU, which to connect the PIPU in the castellation form). The PIPU provides functions of power
conversion from the external power into the power needed by system, battery charge/discharge
management, voice signals processing. Besides the PIPU is the bridge between the TCPU and keypad &
LCD.
2.1.2 Detailed Introduction to Functional Circuit Unit
Power-on Circuit(Battery and Power adapter)
When powering on WL71PIPU, the whole process as follows:
There are two ways of power supply: one is battery, the other is external power. When using the
later one, VEXT_DC up to 5V, then PM6610 begins to work and software startups. At this moment,
some functions of software have been running and the system begins to detect and charge the battery, the
display of LCD in charging status. If holding the Power-off key for 4S (keeping down the voltage of
TERM_ON), the process of Power-on will be closed, the software all in running, searching the net and
being in idle status.
When using the battery, there is only the voltage of VREG_PHONE, the system keeping down the
signal Term_on, PM6610 begins power conversion to the one needed by other modules and software
started up. The programme is the same if we turn on the Power-on switch: when turning it on, PM6610
and software starts up. The software only detects the Power-on switch being holding over 4S, it means
the normal power-on. If not, the process will be closed.
