=============================================================
<b>At Reset</b>:

 While the RST pin is high, ALE and PSEN are weakly pulled high.
 After RST is pulled low, it will take 1 to 2 machine
 cycles for ALE and PSEN to start clocking.

 Driving the ALE and PSEN pins to 0 while reset is active
 could cause the device to go into an indeterminate state.

<b>At ONCE mode</b>

 While the device is in ONCE mode, the Port 0 pins go into a
 float state, and the other port pins and ALE and PSEN
 are weakly pulled high.

<b>At normal mode</b>
 As PSEN is a an output port in normal operating mode
 after reset, user application should take care
 to release PSEN after falling edge of reset signal.
=============================================================