B-31, Figure b-31, Port e registers (pcre, prre, pdre) – Motorola DSP56301 User Manual
Page 355: Gpio
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Programming Sheets
Programming Reference
B
-43
Figure B-31. Port E Registers (PCRE, PRRE, PDRE)
Application:
Date:
Programmer:
Sheet 4 of 4
GPIO
Port E (SCI)
*
= Reserved, Program as 0
23
6
5
4
3
2
1
0
PCE2
PCE1
PCE0
Port E Control Register (PCRE)
X:$FFFF9F Read/Write
Reset = $000000
*
0
*
0
PCn = 1
→
Port Pin configured as ESSI
PCn = 0
→
Port Pin configured as GPIO
23
6
5
4
3
2
1
0
PRE2
PRE1
PRE0
Port E Direction Register (PRRE)
X:$FFFF9E Read/Write
Reset = $000000
*
0
*
0
PDCn = 1
→
Port Pin is Output
PDCn = 0
→
Port Pin is Input
23
6
5
4
3
2
1
0
PDE2
PDE1
PDE0
Port E GPIO Data Register (PDRE)
X:$FFFF9D Read/Write
Reset = $000000
*
0
*
0
if port pin n is GPIO input, then PDn reflects the
value on port pin n
if port pin n is GPIO output, then value written to
PDn is reflected on port pin n
*
0
*
0
*
0
*
0
*
0
*
0
*
0
*
0
*
0
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