EM6605 datasheet(13/43 Pages) NSC

13 / 43 page

EM6605

6.5.PortC

This port can be configured as either input or output (not bitwise selectable). When in input mode it

implements the identical interrupt functions as PortA. The PortC register is used to read data when input

mode and to write data when in output mode. Input mode is set by writing 0 to the I/O control bit CIOPC in

selected by metal option which are active only when selected as input. The output mode is selected by

writing 1 to CIOPC bit, and the terminal follows the bits in the PortC register.

When PortC is used as an input, interrupt functions as described for PortA can be enabled. Input to the

interrupt logic can be direct or via a debounced input. With the debPCN bit at 0 in the Option register all the

PortC inputs are debounced and with the debPCN bit at 1 none of the PortC inputs are debounced.

MPortC is the interrupt mask register for this port and IRQpC is the portC interrupt request register. See

also section 9.

By writing the PA&C bit in the CPIOB data register it is

possible to combine PortA and PortC interrupt requests

(logic AND) as shown in Table 16.

At initial reset, the CPIOC control register is set to 0, and

the port is in input mode. The MPortC register is also

set to 0, therefore disabling interrupts.

Table 17.Ports A&C Interrupt Request

IRQPA

IRQPC

PA&C

Request to CPU

Yes

6.6.PortC registers

Table 18.PortC input/output register - PortC

Bit

Name

Reset

R/W

Description

PC3

R/W

PC3 I/O data

PC2

R /W

PC2 I/O data

PC1

R/W

PC1 I/O data

PC0

R /W

PC0 I/O data

Table 19.PortC Interrupt request register - IRQpC

Bit

Name

Reset

R/W

Description

IRQpc3

input PC3 interrupt request flag

IRQpc2

input PC2 interrupt request flag

IRQpc1

input PC1 interrupt request flag

IRQpc0

input PC0 interrupt request flag

Table 20.PortC interrupt mask register - MportC

Bit

Name

Reset

R/W

Description

MPC3

R/W

interrupt mask for input PC3

MPC2

R/W

interrupt mask for input PC2

MPC1

R/W

interrupt mask for input PC1

MPC0

R/W

interrupt mask for input PC0

EM6605 Datasheet(PDF) 13 Page - National Semiconductor (TI)

EM6605 Datasheet(HTML) 13 Page - National Semiconductor (TI)

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43

Datasheet Download

Link URL