PRELIMINARY

14

PRELIMINARY

Rev F

CPC5750

The lower seven bits of this register determine which of the available 8-bit time slots the CPC5750 uses to transmit

data when in the PCM Mode.

The lower three bits of this register delay the transmit data in the selected time slot by 0 to 7 bits.

2.10 Reserved Register

The Reserved register is not user defined and it’s value should not be modified. The default power up and reset value

of this register is 0 and must not be changed.

2.11 GPIO Control Register

The CPC5750 has four General Purpose I/O pins that can be programmed as inputs or outputs and whose values

can be examined or controlled by the user. This register allows for control and monitoring of external digital nets using

these I/O pins.

2.11.1 DIR(x) (bits [3:0])

Setting a DIR(x) bit to 1, configures the corresponding CPC5750 I/O pin as an output. When the DIR(x) bits are

cleared, i.e. DIR(x) = 0, the corresponding I/O pin will be configured as an input. Following a Power Up or Reset

the CPC5750 configures all four I/O pins as inputs thereby eliminating any possibility of an I/O pin back driving

another output.

2.11.2 D(x) (bits [3:0])

When an I/O is configured as an input, then reading the corresponding D(x) bit of this register gives the logical

state of that input pin. Writing to the D(x) bits of inputs performs no function while writing to the D(x) bit of an I/O

configured as an output determines the state of that output pin. Reading this register returns the current value of

the bits. For an I/O pin configured as an output, reading this register returns the last value written to it’s D(x) bit.

Register

7

6

5

4

3

2

1

0

Address

-

PTC(6)

PTC(5)

PTC(4)

PTC(3)

PTC(2)

PTC(1)

PTC(0)

0x7

Default Value

0

0000000

-

Register

7

6

5

4

3

2

1

0

Address

-

----

PTB(2)

PTB1)

PTB(0)

0x8

Default Value

0

0000000

-

Register

7

6

5

4

3

2

1

0

Address

Reserved

0

0000000

0x9

Register

7

6

5

4

3

2

1

0

Address

GPIO Control

DIR(3)

DIR(2)

DIR(1)

DIR(0)

D(3)

D(2)

D(1)

D(0)

0xA

Default Value

0

0000000

-