A/D Trigger Mode - Renesas M16C/29 Series Hardware Manual

M16C/29 Group

12.2.4 A/D Trigger Mode

A/D trigger mode is used as conversion start trigger for A/D converter in simultaneous sample sweep
mode of A/D conversion or delayed trigger mode 0. This mode is used as conversion start triger of A/D
converter. A/D trigger mode is used in timer B0 and timer B1. In this mode, the timer is activated only by
one trigger. A/D trigger mode is available only for timer B0 and timer B1. Figure 12.2.4.1 shows the
TBiMR register in A/D trigger mode and figure 12.2.4.2 shows the TB2SC register.
Table 12.2.4.1 Specifications in A/D Trigger Mode
Count Source
Count Operation
Divide Ratio
Count Start Condition
Count Stop Condition
Interrupt Request
Generation Timing
TBiIN Pin Function
Read From Timer
Write To Timer (Note 2)
Note 1: A/D conversion is started by the timer underflow.
For details refer to Section 14. A/D Converter.
Note 2: When using in delayed trigger mode 0, set the larger value than the value of the timer B0 register
of the timer B1 register.
Rev.1.00 Nov 01,2004
REJ09B0101-0100Z
f , f , f , f , and f
1 2 8 32
• Down count
• 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
1/(n+1) n: Setting value of TBi register (i=0,1)
0000
When the TBiS (i=0,1) bit in the TABSR register is "1"(count started), TBiEN
(i=0,1) bit in TB2SC register is "1", and the following trigger is generated.
(Selection based on TB2SEL bit of TB2SC register)
• Timer B2 overflow or underflow
• Underflow of Timer B2 interrupt generation frequency counter setting
• After the count value is 0000
• Set the TBiS bit to "0"(count stopped)
Timer underflows (Note 1)
I/O port
Count value can be read by reading TBi register
• 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)
page 115 of 402
Item Specification
C32
-FFFF
16 16
and reload register contents are reloaded
16
12.2 Timer B