M16C28 Datasheet, PDF (140/423 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES

M16C/28 Group (M16C/28, M16C/28B)
12. Timer
12.2.4 A/D Trigger Mode
A/D trigger mode is used together with simultaneous sample sweep mode or delayed trigger mode 0 of
A/D conversion to start A/D conversion. It is used in timer B0 and timer B1 only. In this mode, the timer
starts counting by one trigger until the count value becomes 000016. Figure 12.23 shows the TBiMR
register in A/D trigger mode and Figure 12.24 shows the TB2SC register.
Table 12.9 Specifications in A/D Trigger Mode
Item
Specification
Count Source
f1, f2, f8, f32, and fC32
Count Operation
• Decrement
• When the timer underflows, reload register contents are reloaded before
stopping counting
• When a trigger is generated during the count operation, the count is not
affected
Divide Ratio
1/(n+1) n: Setting value of TBi register (i=0,1)
000016-FFFF16
Count Start Condition
When the TBiS (i=0,1) bit in the TABSR register is "1"(count started), the
TBiEN (i=0,1) in TB2SC register is "1" (A/D trigger mode) and the following
trigger selected by the TB2SEL bit in the TB2SC register
is generated.
• Timer B2 interrupt
• Underflow of Timer B2 interrupt generation frequency counter setting
Count Stop Condition
• After the count value is 000016 and reload register contents are reloaded
Interrupt Request
• Set the TBiS bit to "0"(count stopped)
Timer underflows ⁽¹⁾
Generation Timing
TBiIN Pin Function
I/O port
Read From Timer
Count value can be read by reading TBi register
Write To Timer ⁽²⁾
• When writing in the TBi register during count stopped.
Value is written to both reload register and counter
• When writing in the TBi register during count.
Value is written to only reload register (Transfered to counter when reloaded next)
NOTES:
1. A/D conversion is started by the timer underflow. For details refer to 15. A/D Converter.
2. When using in delayed trigger mode 0, set the larger value than the value of the timer B0 register
to the timer B1 register.
Rev. 2.00 Jan. 31, 2007 ^{page 120} of 385
REJ09B0047-0200