Ei 2 Os Descriptor (Isd) - Fujitsu MB90480 Series Hardware Manual

CHAPTER 3 INTERRUPT
2
3.7.1 EI OS descriptor (ISD)
2
EI OS descriptor (ISD) which is in 000100
byte x 16 channels.
■
Configuration of EI
ISD comprises 8-byte x 16 channels.
80
2
OS Descriptor (ISD)
Figure 3.7-2 Configuration of EI
MSB
ISD Starting Address
(000100 + 8 × ICS)
H
MSB: Highest bit
LSB : Lowest bit
to 00017F of built-in RAM is consists of 8-
H H
2
OS Descriptor (ISD)
Data counter upper 8bit (DCTH)
Data counter lower 8bit (DCTL)
I/O address pointer upper 8bit (IOAH)
I/O address pointer lower 8bit (IOAL)
2
EI OS Status register(ISCS)
Buffer address pointer upper 8bit (BAPH)
Buffer address pointer middle 8bit (BAPM)
Buffer address pointer lower 8bit (BAPL)
LSB
H
L