emWin - SEGGER Microcontroller

29.3 Hardware interface configuration
The following explains how to configure the hardware communication between display
driver and display controller.
29.3.1 Direct interface
The hardware interface configuration of drivers using a direct interface is done by
specifying the address of the video memory. Normally the routine
LCD_SetVRAMAddrEx() should be used for this. Normally nothing else should be done
to enable access to the video memory for the driver. For details please refer to “Display
driver API” on page 993.
29.3.2 Indirect interface
There are 2 kinds of display drivers:
• Run-time configurable drivers
• Compile-time configurable drivers
Configuring these kinds of drivers works differently:
• Run-time configuration means the driver can be compiled without being configured.
The configuration is done at run-time. This type of driver can still be configured
at run-time when placed in a library.
• A compile-time configurable driver requires the configuration in a configuration
header file, which is included at compile-time of the driver.
29.3.2.1 Run-time configuration
Run-time configurable drivers do not need to be configured at compile time. So this
drivers can be used in a precompiled library.
Each driver has its own function(s) for setting up the hardware interface. This is done
by passing a pointer to a GUI_PORT_API structure containing function pointers to the
hardware routines to be used:
Elements of GUI_PORT_API
Element Data type
8 bit interface
Description
pfWrite8_A0 void (*)(U8 Data)
pfWrite8_A1 void (*)(U8 Data)
pfWriteM8_A0 void (*)(U8 * pData, int NumItems)
pfWriteM8_A1 void (*)(U8 * pData, int NumItems)
pfRead8_A0 U8 (*)(void)
pfRead8_A1 U8 (*)(void)
pfReadM8_A0 void (*)(U8 * pData, int NumItems)
UM03001 User & Reference Guide for emWin V5.18 © 1997 - 2012 SEGGER Microcontroller GmbH & Co. KG
915
Pointer to a function which writes
one byte to the controller with C/D
line low.
Pointer to a function which writes
one byte to the controller with C/D
line high.
Pointer to a function which writes
multiple bytes to the controller with
C/D line low.
Pointer to a function which writes
multiple bytes to the controller with
C/D line high.
Pointer to a function which reads
one byte from the controller with
C/D line low.
Pointer to a function which reads
one byte from the controller with
C/D line high.
Pointer to a function which reads
multiple bytes from the controller
with C/D line low.