XC68HC08KH12 Motorola, XC68HC08KH12 Datasheet - Page 198

• Manufacturer Part Number: XC68HC08KH12
• Description: MICROCONTROLLER
• Manufacturer: Motorola

I/O Ports
12.7.3 Port-E Optical Interface Enable Register
Advance Information
198
Address:
Port E pins PTE3–PTE0, each has an optical coupling interface circuit
which is specially built for optical mouse application. Bits [1:0] of the
Optical Interface Enable register enable or disable the interface circuit in
each port E pins PTE3–PTE0, whilst bits [7:2] define the reference level
for the optical interface circuit for optimum performance.
OIEX — Optical Interface Enable X.
OIEY — Optical Interface Enable Y.
Reset:
1. X = don’t care
2. Hi-Z = high impedance
3. Writing affects data register, but does not affect input.
Read:
Write:
DDRE
This enables optical interface on PTE0 and PTE1 pins. It also enables
the voltage divider circuit.
This enables optical interface on PTE2 and PTE3 pins. It also enables
the voltage divider circuit.
Bit
0
1
Figure 12-16. Optical Interface Enable Register E (EOIER)
1 = PTE0 and PTE1 optical interface enabled.
0 = PTE0 and PTE1 optical interface disabled.
1 = PTE2 and PTE3 optical interface enabled.
0 = PTE2 and PTE3 optical interface disabled.
YREF2
$001C
Bit 7
0
PTE
X
Bit
X
(1)
YREF1
6
1
I/O Pin Mode
Input, Hi-Z
Table 12-6. Port E Pin Functions
I/O Ports
Output
YREF0
5
0
(2)
XREF2
Accesses to
4
0
Read/Write
DDRE[4:0]
DDRE[4:0]
DDRE
XREF1
3
1
MC68HC(7)08KH12
XREF0
PTE[4:0]
Read
2
0
Pin
Accesses to PTE
OIEY
1
0
PTE[4:0]
MOTOROLA
PTE[4:0]
Write
—
Rev. 1.0
OIEX
Bit 0
0
(3)