ra8806 RAIO Technology Inc., ra8806 Datasheet - Page 64

• Manufacturer Part Number: ra8806
• Description: Two Layers Character/graphic Lcd Controller
• Manufacturer: RAIO Technology Inc.

Preliminary Version 1.2
RAiO
6-8
TECHNOLOGY INC.
The RA8806 provides an interrupt output (INT) for MPU to indicate the status of RA8806. And a busy
output to indicate the RA8806 is in busy state. Both signals could be set to active high or active low by
register.
6-8-1 Interrupt
Interrupt and Busy
RA8806 provides an Interrupt signal (INT) for following event:
These interrupt events can be masked or active respectively. It is controlled by the REG[0Fh], the
mask and status registers.
Besides, RA8806 also provide a software access interrupt function. When user system don’t support
hardware interrupt signal, they can use polling method to achieve the software interrupt.
To access hardware interrupt, user needs to set corresponding Interrupt Mask bit to 1(Refer to
register INTR). The steps are:
To apply the software interrupt method, users don’t need extra setting. Just reading the status bit of
register INTR to check the interrupt event. BTW, interrupt mask can only disable the hardware
interrupt, but can’t disable the status of INTR.
Example-1:
The Figure 6-32 is an example of INT timing for Wake-up event. RA8806 provides three wake-up
event. Please refer to Section 6-7-4 “Sleep Mode” for the detail.
Touch Panel touched event is happen.
Key-Scan enable and key is pressed
Wake-up event occurs when Sleep mode.
RA8806 generate the interrupt signal to MPU.
After finishing the current instruction, MPU hardware will jump the PC(Program counter)
to Interrupt Service Routine(ISR).
In the same time that RA8806 generate the interrupt, the interrupt status is set
to ”1”(REG[0Fh] Bit[2:0]). (For example, if key-scan interrupt activates, the Key-Scan
status will be set to 1).
Wake-Up
Event
INT
Figure 6-32: Interrupt Timing(1)
64/184
t
INTST
Two Layers Character/Graphic LCD Controller
www.raio.com.tw
RA8806