xe8802 Semtech Corporation, xe8802 Datasheet - Page 67

• Manufacturer Part Number: xe8802
• Description: Data Acquisition Soc With 16+10 Bit Zoomingadc? Embedded Risc Controller And Lcd Driver
• Manufacturer: Semtech Corporation

9.1
The XE8000 chips support 8 event sources, divided into 2 levels of priority.
9.2
An event is different from an interrupt in that it does not modify the program counter (PC). Events are used by two
microcontroller instructions.
First of all, events are useful to wake-up the microcontroller when it is in HALT. The software execution then simply
resumes at the instruction next to the HALT instruction. The second instruction is the conditional jump on event
(JEV). The jump is executed if one of the event flags in the stat register is set. In all other cases, the occurrence of
an event has no effect.
The event handler allows to manage 8 event sources individually. The 8 event sources are divided into 2 levels of
priority: High (4 event sources) and Low (4 event sources). Those 2 levels of priority are directly mapped to those
supported by the CoolRisc™ (EV0and IN1; see CoolRisc™ documentation for more information).
Additional functions are given that allow fast detection of the highest priority event that has been activated.
9.3
The addresses given in Table 9-1 are the default values and may be different in some products.
9-2
Features
Overview
Register map
7
6
5
4
3
2
1
0
pos.
RegEvn[7]
RegEvn[6]
RegEvn[5]
RegEvn[4]
RegEvn[3]
RegEvn[2]
RegEvn[1]
RegEvn[0]
RegEvn
XE8802 Sensing Machine Data Acquisition MCU
r
c1
r
c1
r
c1
r
c1
r
c1
r
c1
r
c1
r
c1
rw
Table 9-1: EVN handler registers.
0 nresetglobal
0 nresetglobal
0 nresetglobal
0 nresetglobal
0 nresetglobal
0 nresetglobal
0 nresetglobal
0 nresetglobal
Register name
RegEvnPriority
Table 9-2: RegEvn
RegEvnEvn
RegEvnEn
RegEvn
reset
with ZoomingADC™ and LCD driver
event #7 (high priority)
clear event #7 when written 1
event #6 (high priority)
clear event #6 when written 1
event #5 (high priority)
clear event #5 when written 1
event #4 (high priority)
clear event #4 when written 1
event #3 (low priority)
clear event #3 when written 1
event #2 (low priority)
clear event #2 when written 1
event #1 (low priority)
clear event #1 when written 1
event #0 (low priority)
clear event #0 when written 1
function
D0405-134