PSD501B1 datasheet(44/153 Pages) STMICROELECTRONICS

44 / 153 page

PSD5XX Family

9.3.7 Alternate Function In

This mode is per-pin configurable and enables the user to define the pins in Port E to

perform Alternate function. Alternate Function includes inputs to Counter/Timers and APD

clock.

t Configuration

1. Select input functions in PSD configuration

2. PSD compiler assigns pins for the selected function.

9.3.8 Peripheral I/O

This mode enables the microcontroller to read or write to a peripheral though Port A.

When there is no read/write operation, Port A is tri-stated. One of the applications of

Peripheral I/O is in a DMA based design.

t Configuration

1. Declare the pins used as Peripheral I/O in the ABEL file.

2. Write logic equations for PSEL0 and PSEL1.

3. Write a “1” to the PIO bit in the VM Register to activate the Peripheral I/O operation.

See the section on Peripheral I/O for a detailed description.

9.3.9 Open Drain Outputs

This mode enables the user to configure Port C and D pins as open drain outputs. CMOS

output is the default configuration. Writing “1” to the corresponding bit in the Open Drain

Port Mode

Port A

Port B

Port C

Port D

Port E

Standard MCU I/O

Yes

PLD I/O

Yes

Input Only

Yes

Address Out

Yes

Address In

Yes

Data Port

Yes

Special Function Out

Yes

Alternate Function In

Yes

Peripheral I/O

Yes

Open Drain

Yes

*For external decoding. Cannot be latched by ALE.

Table 11. Operating Modes of the I/O Ports

The following table summarizes the operating modes of the I/O ports. Not all functions are

available to every port.

I/O Ports

(Cont.)

PSD501B1 Datasheet(PDF) 44 Page - STMicroelectronics

PSD501B1 Datasheet(HTML) 44 Page - STMicroelectronics

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 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL