
PSD3XX Famly
2-26
Component
Signals
Contents
All = 1 (Note 23)
CS0–CS10
PAD
CSADIN, CSADOUT1, 
CSADOUT2, CSIOPORT, 
RS0, ES0 – ES7
n/a
n/a
n/a
n/a
All = 0 (Note 23)
Data register A
Direction register A
Data register B
Direction register B
0
0
0
0
NOTE:
 23. All PAD outputs are in a non-active state.
Table 11.
Internal States
During and After
Reset Cycle
Signal
Configuration Mode
Condition
Input
Input
Input
Input
Low
Input
High
Tri-stated
Input
High
AD0/A0–AD7/A7
A8–A15
All
All
I/O
Tracking AD0/A0–AD7
Address outputs A0–A7
I/O
CS7–CS0 CMOS outputs
CS7–CS0 open drain outputs
Address inputs A16–A18
CS8–CS10 CMOS outputs
PA0–PA7)
(Port A)
PB0–PB7
(Port B)
PC0–PC2
(Port C)
Table 10. 
Signal States
During Reset
Active
(RESET)
RESET
This is an asynchronous input pin that clears and initializes the PSD3XX. Reset polarity is 
programmable (active low or active high). Whenever the PSD3XX reset input is driven
active for at least 100 ns, the chip is reset. The PSD3XX must be reset at power up before
it can be used. Tables 10 and 11 indicate the state of the part during and after reset.
For the PSD3XXL, reset is an asynchronous low signal only. Whenever the reset input is
driven low for at least 500 ns, the chip is reset. After reset becomes high, the chip will be
operational only after an additional 500 ns. See Figure 11. Note that during boot-up, the
part is not automatically reset internally and does require an external reset. Tables 10 and
11 indicate the state of the part during and after reset.
A19/CSI
When configured as CSI, a high on this pin deselects, and powers down, the chip. 
A low on this pin puts the chip in normal operational mode. For PSD3XX states during the
power-down mode, see Tables 12 and 13, and Figure 12.
In A19 mode, the pin is an additional input to the PAD. It can be used as an address line
(CADLOG3 = 1) or as a general-purpose logic input (CADLOG3 = 0). A19 can be 
configured as ALE dependent or as transparent input (see Table 8). In this mode, the chip
is always enabled.
Control Signals
(Cont.)