Lucent Technologies MN10285K Laptop User Manual


 
Timers
16-Bit Timer Setup Examples
Panasonic Semiconductor Development Company MN102H75K/F75K/85K/F85K LSI User Manual
94
Panasonic
4.11 16-Bit Timer Setup Examples
4.11.1 Setting Up an Event Counter Using Timer 4
In this example, timer 4 counts the TM4IB input signal (B
OSC
/4 = 6 MHz or less)
and generates an interrupt on the second and fifth cycles.
To set up timer 4:
Use the MOV instruction for this
setup and only use 16-bit write
operations.
This step stops the TM4BC
count and clears both TM4BC
and the S-R flip-flop to 0.
1. Set the operating mode in the timer 4 mode register (TM4MD). Disable
timer 4 counting and interrupts. Select up counting. Select TM4IB as the
clock source.
TM4MD (example) x’00FE80’
2. Set the divide-by ratio for timer 4. To divide the TM4IB input signal by 5,
write x’0004’ to timer 4 compare/capture register A (TM4CA). (The valid
range for TM4CA is x’0001’ to x’FFFE’.)
A. Chip Level
B. Block Level
Figure 4-27 Block Diagram of Event Counter Using Timer 4
TM4IB
P2
P6
P4
P5
CORE
Interrupts
Timers 0-3
Timers 4-5
ROM, RAM
Bus Controller
Serial I/Fs
ADC
(B
OSC
/4)
up
TM4BC
Timer 4
TM4CA
TM4CAX
TM4CB
TM4CBX
TM4IB
(TM4OA)
TQ
TQ
R
S
Q
Controller
Bit:1514131211109876543210
TM4
EN
TM4
NLD
——
TM4
UD1
TM4
UD0
TM4
TGE
TM4
ONE
TM4
MD1
TM4
MD0
TM4
ECLR
TM4
LP
TM4
ASEL
TM4
S2
TM4
S1
TM4
S0
Setting:0000000000010010