MN5572 Datasheet, PDF (21/28 Pages) Panasonic Semiconductor – Gray Scale Font Engine

MN5572
I Operation
2. Operating Procedures (continued)
2. 4. Gray-scale data readout processing (continued)
• Gray-scale data readout processing flowchart (continued)
• Has 1 frame completed?
Processing terminates if the gray-scale data readout operation has completed the output of the gray-scale data
for a single figure or font character. The IC divides the gray-scale data into units internally, and if there is still
data that must be output (REC = 0), another read operation must be performed again by checking the status
register.
2. 5. Interrupt signal wait processing
• Interrupt signal wait processing flowchart
start
MIS = 1→0
Initialization complete
Interrupt signal check
IRQ = "L"
IRQ = "H"
Status register check
(status read)
IRQ = "H"→"L"
Interrupt verification
PMS = 00
RMS = 11
Path data write
Gray-scale data readout
• Interrupt signal wait processing flowchart description
The IC internal state changes can be verified from the generated interrupt signal.
• Interrupt signal check
The interrupt signal (IRQ) is monitored until the interrupt generation conditions set in the IC's mask register
are met and the IC asserts (sets to the high level) the interrupt signal.
• Status register check
The status register is read and checked.
After the status register is read, the IC deasserts the interrupt signal (IRQ).
• Interrupt verification
The reason the interrupt was generated is verified from the values of the MIS, PMS, and RMS fields in the
status register.
This determines what processing must be performed next.
Note: Interrupt signal wait processing can not be used in PCI mode.
In that case, the IC internal state changes should be determined by periodically reading the status register.
SDF00008BEM
21