 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
68901P05 Datasheet(PDF) 8 Page - STMicroelectronics |
|
||||||||||||||||||||||||||||||
68901P05 Datasheet(HTML) 8 Page - STMicroelectronics |
|
|
8 / 33 page  Figure 10 : A Conceptual Circuit of an Interrupt Channel. There are two end-of-interrupt modes : the automat- ic end-of-interrupt mode and the software end-of-in- terrupt mode. The mode is selected by writing a one or a zero to the S bit of the Vector Register (VR). If the S bit of the VR is a one, all channels operate in the software end-of-interrupt mode. If the S bit is a zero, all channels operate in the automatic end-of- interrupt mode, and a reset is held on all in-service bits. In the automatic end-of-interrupt mode, the pending bit is cleared when that channel passes its vector. At that point, no further history of that inter- rupt remains in the MK68901 MFP. In the software end-of-interrupt mode, the in-service bit is set and the pending bit is cleared when the channel passes its vector. With the in-service bit set, no lower priority channel is allowed to request an interrupt or to pass its vector during an acknowledge sequence ; how- ever, a lower priority channel may still receive an in- terrupt and latch it into the pending bit. A higher prio- rity channel may still request an interrupt and be ac- knowledged. The in-service bit of a particular chan- nel may be cleared by writing a zero to the corre- sponding bit in ISRA or ISRB. Typically, this will be done at the conclusion of the interrupt routine just before the return. Thus no lower priority channel will be allowed to request service until the higher priority channel is complete, while channels of still higher priority will be allowed to request service. While the in-service bit is set, a second interrupt on that chan- nel maybe received and latched into the pending bit, though no service request will be made in re- sponse to the second interrupt until the in-service bit is cleared. ISRA and ISRB may be read at any time. Only a zero may be written into any bit of ISRA and ISRB ; thus the in-service bits may be cleared in soft- ware but cannot be set in software. This allows any one bit to be cleared, without altering any other bits, simply by writing all ones except for the bit position to be cleared to ISRA or ISRB, as with IPRA and IPRB. Figure 11 a : A Conceptual Circuit of the MK68901 MFP Daisy Chaining. V000356 V000357 MK68901 8/33 |
Similar Part No. - 68901P05 |
|
Similar Description - 68901P05 |
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
