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3-4
PPSM PPSM Programming
Programmer’s Manual
regions defined in PPSM as active areas. Active area provides an easy method
for applications to receive pen input samples from the input panel without the
need to monitor the hardware constantly. PPSM uses interrupt to perform pen
sampling, maximizing processor power utilization.
An active area is defined as a rectangular region of the input panel where interrupt
messages are generated to the application when the region is pressed. Active
areas only generate messages to the application that created the area. An
example of an active area is an icon, an action button, scratch pad or drawing
area.
When application needs to perform pen input, it must define the area location and
register each active area with PPSM before the area can respond to a pen input.
All remaining areas on the input panel not registered with PPSM will not generate
any information to the application. For details on active areas and input methods,
please refer to Chapter 4 - Pen Input Handling and Chapter 5 - Character Input
Methods
3.2.2
Messages from PPSM
PPSM application should take a pro-active role, i.e., an event driven approach.
When external events occur, such as pressing of the input panel, PPSM system
automatically intercepts and interprets the event. If the events require attention
from the application, such as an active area being pressed, or incoming data from
UART, PPSM will package the data in the pre-defined message format and send
to the waiting application’s interrupt buffer (please refer to
Chapter 15 - Interrupt
Handling
). However, if the event is not intended for the application, such as
pressing of input panel that is not defined as active area, or timeout for going into
power saving mode, the event is handled by PPSM internally without any
message sent to the application.
Upon receiving soft interrupt messages sent from PPSM, application tasks should
act upon the nature of the message. There are a set of pre-defined messages
types for different types of interrupts (refer to
Section 15.1 - System Interrupts
and
Section 15.2 - Device Interrupts
).
Application tasks can receive the soft interrupt messages by using the system the name will be in upper case.
IrptGetData(). The application task should call this tool periodically in the
program’s flow to check for any incoming events (refer to
Section 29.1 -
IrptGetData
).
3.3
Data Representation
PPSM is a 32-bit system.
Table 3-1
shows the data types used in PPSM
Table 3-1 Data type definition used in PPSM
Data Type
Description
Size (in bytes)
U8
unsigned byte
1
P_U8
unsigned byte pointer
4
Personal Portable System Manager
Programmer’s Manual
3-5
For consistency, a set of guidelines is set up for the naming conventions during
software development. This is not a fixed requirement, but a recommendation.
All procedure names are in lower case except the first letter of each word within
Example 3-1 Procedure names
PenInit()
PagerCheck()
DrawDot()
Constants and Labels
All constants and labels are in upper case, underscores are permitted.
Example 3-2 Constants and labels
DISPLAY_MODE
DEFAULT_MODE
S8
signed byte
1
P_S8
signed byte pointer
4
U16
unsigned short
2
P_U16
unsigned short pointer
4
S16
signed short
2
P_S16
signed short pointer
4
U32
unsigned int
4
P_U32
unsigned int pointer
4
S32
signed int
4
P_S32
signed int pointer
4
STATUS
unsigned short
2
TEXT
unsigned short
2
P_TEXT
unsigned short pointer
4
P_VOID
void pointer
4
Table 3-1 Data type definition used in PPSM
Data Type
Description
Size (in bytes)
F
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n
.