M16C62A Datasheet, PDF (83/242 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Timer B
Mitsubishi microcomputers
M16C / 62A Group (80-pin)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(1) Timer mode
In this mode, the timer counts an internally generated count source. (See Table 1.13.6.) Figure 1.13.17
shows the timer Bi mode register in timer mode.
Table 1.13.6. Timer specifications in timer mode
Item
Specification
Count source
Count operation
f1, f8, f32, fC32
• Counts down
• When the timer underflows, it reloads the reload register contents before
continuing counting
Divide ratio
Count start condition
1/(n+1) n : Set value
Count start flag is set (= 1)
Count stop condition
Count start flag is reset (= 0)
Interrupt request generation timing The timer underflows
TBiIN pin function
Read from timer
Programmable I/O port
Count value is read out by reading timer Bi register
Write to timer
• When counting stopped
When a value is written to timer Bi register, it is written to both reload register and counter
• When counting in progress
When a value is written to timer Bi register, it is written to only reload register
(Transferred to counter at next reload time)
Note: Timer B1 works exclusively as an internal timer since timer B1 does not have input port (TB1IN).
Timer Bi mode register
b7 b6 b5 b4 b3 b2 b1 b0
00
Symbol
TBiMR(i=0 to 5)
Address
039B16 to 039D16
035B16 to 035D16
When reset
00XX00002
00XX00002
Bit symbol
TMOD0
TMOD1
MR0
MR1
Bit name
Function
Operation mode select bit
b1 b0
0 0 : Timer mode
Invalid in timer mode
Can be “0” or “1”
RW
MR2
0 (Must always be “0” in timer mode ; i = 0, 3)
Nothing is assiigned (i = 1, 2, 4, 5).
In an attempt to write to this bit, write “0”. The value, if read, turns out
to be indeterminate.
MR3
Invalid in timer mode.
In an attempt to write to this bit, write “0”. The value, if read in
timer mode, turns out to be indeterminate.
TCK0
TCK1
Count source select bit
b7 b6
0 0 : f1
0 1 : f8
1 0 : f32
1 1 : fC32
Note 1: Timer B0, timer B3.
Note 2: Timer B1, timer B2, timer B4, timer B5.
(Note 1)
(Note 2)
Figure 1.13.17. Timer Bi mode register in timer mode
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