EM6605 EM Microelectronic, EM6605 Datasheet - Page 15

• Manufacturer Part Number: EM6605
• Description: 4 bit Microcontroller
• Manufacturer: EM Microelectronic

6.7. PortD
The EM6605 has one all purpose I/O port similar to PortC but without interrupt capability. The PortD
register is used to read input data when an input and to write output data for output. The input line can be
pulled down (metal option) when the port is used as input. Input mode is set by writing 0 to the I/O control
bit CIOPD in register CPIOB, and the terminal becomes high impedance. On each terminal Pull-Up/Down
resistor can be selected by metal option which are active only when selected as input.
Output mode is set by writing 1 to the control bit CIOPD. Consequently, the terminal follows the status of
the bits in the PortD register. If Serial Write Buffer function is enabled PD0 and PD1 terminals of PortD
output serial clock and serial data respectively. For details see 11.0 Serial Write Buffer.
6.8. PortD registers
Table 21.PortD Input/Output register - PortD
Table 22.Ports control register - CPIOB
Figure 9.Port D
Bit
3
2
1
0
Bit
3
2
1
0
Name
PD3
PD2
PD1
PD0
Name
-
CIOPD
CIOPC
PA&C
Reset
0
0
0
0
Reset
-
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Description
not used
I/O PortD select
I/O PortC select
Logical AND of IRQ’s from PortA & PortC
PD3 I/O data
PD2 I/O data
PD1 I/O data
PD0 I/O data
Description
© EM Microelectonic-Marin SA, 02/99, Rev. B/243
EM6605
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