Motorola APX 1000 - Figure 3-22. Power-Up Timing Regulators

Theory of Operation: Controller 3-31
3.2.2.1.4 Power-up Timing
The powering up of the radio starts with the MAKO. Once the radio knob is pressed to 'ON' and
battery voltage is supplied, a pass FET is activated to deliver battery voltage to MAKO and external
regulators. The external 3.6 V is first turned on then MAKO activates its 24.576 MHz clock, and the
remaining regulators begin to turn on. Once all the regulators have turned on, MAKO releases its
reset. The CPLD is then powered on from the 1.875 V external regulator and takes MAKO 24.576
MHz clock and divides it to 32.768 kHz in order to provide for OMAP. OMAP starts to power up upon
receiving voltages 1.4 V, 1.85 V, and the 32.768 kHz clock. OMAP than activates it 12 MHz clock and
releases its reset. It then starts to run the boot loader stored in flash. A more detailed timing view of
the regulators is shown in Figure 3-22.
Figure 3-22. Power-up Timing Regulators
fet_en
20ms
1ms
210us
1ms
252us
210us
210us
210us
1ms
2ms
1ms
1ms
1ms
1ms
14ms
1ms
4ms
41.6us(1024clk24)
rcosc
sw1_enldo
sw1_en
sw1_boost_slimit
clk24_cnten
clk24_val
clk24
sw1_clk
sw2_clk
sw2_ondc
sw2_softstart[0]
sw2_softstart[1]
sw2_softstart[2]
v9_on
v4_on
v3_on
v8_on
v2_on
v6_on
v7_on
v10_on
sys_rstx
rcosc_en