m37905 Renesas Electronics Corporation., m37905 Datasheet - Page 129

• Manufacturer Part Number: m37905
• Description: Mitsubishi 16-bit Single-chip Microcomputer 7700 Family / 7900 Series
• Manufacturer: Renesas Electronics Corporation.

TIMER A
7.4 Event counter mode
Fig. 7.4.6 Timer Aj (j = 2 to 4, 7 to 9) mode register when two-phase pulse signal processing function
7-26
7.4.4 Selectable functions
The following describes the selectable pulse output, and two-phase pulse signal processing functions.
(1) Pulse output function
(2) Two-phase pulse signal processing function (Timers Aj)
The pulse output function is selected by setting the pulse output function select bit (bit 2 at addresses
56
pulse output pin regardless of the corresponding bits of the port P6, port P2, and port P4 direction
registers. The TAi
or overflow occurs. (Refer to Figure 7.3.5).
When the count start bit (addresses 40
For timer Aj (j = 2 to 4, 7 to 9), the two-phase pulse signal processing function is selected by setting
the timer Aj two-phase pulse signal processing select bits (bits 5 to 7 at addresses 44
to “1.” (See Figure 7.4.5.) Figure 7.4.6 shows the timer Aj mode register when the two-phase pulse
signal processing function is selected.
For timers with two-phase pulse signal processing function selected, the timer counts two kinds of
pulses of which phases differ by 90 degrees. There are two types of the two-phase pulse signal
processing: normal processing and quadruple processing. In timer Am (m = 2, 3, 7, 8), normal
processing is performed; in timer An (n = 4, 9), quadruple processing is performed.
For the port P6, port P2, and P4 direction registers’ bits corresponding to the pins used for two-phase
pulse input, be sure to set these bits for the input mode.
16
is selected
to 5A
16
, D6
16
to DA
OUT
X
b7
: It may be either “0” or “1.”
pin outputs a pulse of which polarity is inverted each time a counter underflow
b6
16
b5
0
) to “1.” When this function is selected, the TAi
b4
1
b3
0 0 0 1
7905 Group User’s Manual Rev.1.0
b2
b1
16
b0
, 41
16
Timer A2 mode register (Address 58
Timer A3 mode register (Address 59
Timer A4 mode register (Address 5A
Timer A7 mode register (Address D8
Timer A8 mode register (Address D9
Timer A9 mode register (Address 5D
) is “0” (count stopped), the TAi
OUT
16
16
16
16
16
16
pin is forcibly set for the
OUT
)
)
)
)
)
)
pin outputs “L” level.
16
and C4
16
)