Timer Mode - Renesas M16C Series User Manual

M30240 Group
Timer Bi register (Note)
(b15)
b7
Count start flag
b7 b6
Figure 1.72: Timer B-related registers (2)

1.2.22.1 Timer mode

In this mode, the timer counts an internally generated count source as shown in Table 1.23 .
Table 1.23: Timer B timer specifications in timer mode
Item
Count source
Count operation
Divide ratio
Count start condition
Count stop condition
Interrupt request
generation timing
Read from timer
Write to timer
Note: Timer B2 does not generate an interrupt; it is used as a prescaler only.
Rev.1.00 Sep 24, 2003 Page 77 of 360
(b8)
b0 b7 b0
• Timer mode
Counts the timer's period
Note: Read and write data in 16-bit units.
Symbol
b5 b4 b3 b2 b1 b0
TABSR
Bit symbol
TA0S Timer A0 count start flag
TA1S Timer A1 count start flag
TA2S Timer A2 count start flag
TA3S Timer A3 count start flag
TA4S Timer A4 count start flag
TB0S Timer B0 count start flag
TB1S Timer B1 count start flag
TB2S Timer B2 count start flag
f1, f8, f32
• Counts down
• When the timer underflows, it reloads the reload register contents before continuing counting
1/(n+1) n: Set value
Count start flag is set (= 1)
Count start flag is reset (= 0)
The timer underflows (see Note)
Count value is read out by reading timer Bi register
• When counting stopped
When a value is written to Timer Bi register, it is written to both reload register and counter
• When counting is in progress
When a value is written to Timer Bi register, it is written to only reload register
(Transferred to counter at the next reload time)
Symbol Address
TB0 0391
16
TB1 0393
16
TB2 0395
16
Function
Values that can be set
0000 to FFFF
16
Address When reset
0380 00
16 16
Bit name Function
0 : Stops counting
1 : Starts counting
Specification
When reset
, 0390 Indeterminate
16
, 0392 Indeterminate
16
, 0394 Indeterminate
16
R W
16
R W
Timer B