![](http://datasheet.mmic.net.cn/290000/XPC801ZP25_datasheet_16187868/XPC801ZP25_11.png)
TABLE OF CONTENTS (Continued)
Paragraph
Number
Page
Number
Title
MOTOROLA
MPC801 USER’S MANUAL
xiii
12.12.2.5
12.12.2.6
12.12.2.7
12.12.2.8
12.12.2.9
12.12.2.10
Real-Time Clock Status and Control Register ............12-26
Real-Time Clock Register ...........................................12-27
Real-Time Clock Alarm Register ................................12-27
Periodic Interupt Status and Control Register ............12-27
Periodic Interrupt Timer Count Register .....................12-28
Periodic Interrupt Timer Register ................................12-29
Section 13
External Bus Interface
13.1
13.2
13.2.1
13.3
13.4
13.4.1
13.4.2
13.4.2.1
13.4.2.2
13.4.3
13.4.4
13.4.5
13.4.6
13.4.6.1
13.4.6.2
13.4.6.3
13.4.7
13.4.7.1
13.4.7.2
13.4.7.3
13.4.8
13.4.8.1
13.4.8.2
13.4.8.3
13.4.8.4
13.4.9
13.4.10
13.4.10.1
Features .............................................................................................13-1
Transfer Signals .................................................................................13-2
Control Signals .........................................................................13-3
Signal Descriptions .............................................................................13-4
Operations on the Bus ........................................................................13-8
Basic Transfer Protocol ............................................................13-8
Single Beat Transfers ...............................................................13-8
Single Beat Read Flow .................................................13-9
Single Beat Write Flow ...............................................13-12
Burst Transfers .......................................................................13-16
The Burst Mechanism ............................................................13-16
Transfer Alignment and Packaging ........................................13-25
Arbitration Phase Signals .......................................................13-27
Bus Request ...............................................................13-28
Bus Grant ....................................................................13-28
Bus Busy .....................................................................13-29
Address Transfer Phase-Related Signals ..............................13-32
Transfer Start ..............................................................13-32
Address Bus ...............................................................13-32
Transfer Attributes ......................................................13-32
Termination Signals ................................................................13-35
Transfer Acknowledge ................................................13-35
Burst Inhibit .................................................................13-35
Transfer Error Acknowledge .......................................13-35
Protocol for Termination Signals .................................13-35
Storage Reservation Protocol ................................................13-37
Exception Control Cycles .......................................................13-40
RETRY ........................................................................13-40