Intel
®
81341 and 81342—Timers
Intel
®
81341 and 81342 I/O Processors
Developer’s Manual
December 2007
812
Order Number: 315037-002US
12.3
Timer State Diagram
shows the common states of the Timer Unit. For uncommon conditions see
Section 12.5, “Uncommon TCRX and TRRX Conditions” on page 820
.
Figure 117. Timer Unit State Diagram
A6770-01
TMRx.enable = 0
TMRx.reload = 0
TMRx.pri = 0
TMRx.csel1:0 = 0
IPND.tip = 0
TMRx.enable = 1
TMRx.reload = user value
TMRx.pri = user value
TMRx.csel1:0 = user value
TMRx.reload = user value
TMRx.pri = user value
TMRx.csel1:0 = user value
TC = 1
IPND.tip = 1
TMRx.enable = 0
TC = 0
TMRx.enable = 1
TCRx = TRRx
Bus Clock
"Uncommon TCRX and
TRRX Conditions"
Hardware / Software
Reset
Initial TCRx Check
TC = 0
Bus Clock or SW Read
SW Write (TMRx.enable = 1
SW Write
(TMRx.enable = 0)
Clock Unit Tick
and TCRx != 0
TCRx=0
TMRx.enable = 0
SW Read
SW Write
SW Read
TMRx.enable = 1
SW Read/Write & Reload = 0
IDLE
TCRx != 0
TCRx = 0
SW Write
Reload = 1
Decrement
TCRx
TC Detected
State