MC68HC05X16 Datasheet, PDF (61/232 Pages) Freescale Semiconductor, Inc – High-density complementary metal oxide semiconductor HCMOS) microcontroller unit

Freescale Semiconductor, Inc.
Read buffer output
(a)
A
Y
Data direction register bit DDRn
DDRn A
1
0
Y
0
4
1
1
1

 Normal operation – tri state
0
0 tri state _
0
1 tri state ^
(b)
1
0
low 
1
1
—

 ‘Open-drain’
0
0
high _
0
1
high ^
V_DD
VDD
Px0
‘Open-drain’ output
(c)
DDRx, bit 0 = 0
Portx, bit 0 = 0
Figure 4-3 Port logic levels
DDRx, bit 0 = 0
Portx, bit 0 = 0
MC68HC05X16
INPUT/OUTPUT PORTS
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