Renesas Hitachi H8S/2191, Hardware Manual

Page: 343 / 1065

Rev. 2.0, 11/00, page 316 of 1037
14.3 Operation
14.3.1 8-bit Reload Timer (TMJ-1)
The TMJ-1 is an 8-bit reload timer. As the clock source, dividing clock or edge signals through
the
,54 pin are being used. By selecting the edge signals through the ,54 pin, it can also be
used as an event counter. While it is working as an event counter, its reloading function is
workable simultaneously. When data are written into the reloading register TLJ, these data will
be written into the counter TCJ simultaneously. Also, when the counter TCJ underflows, the
data of the reloading register TLJ will be reloaded to the counter TCJ.
When the counter underflows, TMJ1I interrupt requests will be issued.
The underflow will be toggled and, by a appropriate selection of the dividing clock, buzzer
outputs will be issued or carrier frequencies for remote controlling transmissions can be
acquired.
The TMJ-1 and TMJ-2, in combination, can be used as a 16-bit reload timer. Nonetheless, when
they are being used, in combination, as a 16-bit timer, word command only is valid and the TCK
works as the down counter for the upper 8 bits and the TCJ works as the down counter for the
lower 8 bits, means a reloading register of total 16 bits.
When data are written into a 16-bit reloading register, the same data will be written into the 16-
bit counter.
Also, when the 16-bit counter underflows, the data of the 16-bit reloading register will be
reloaded into the counter.
Even when they are making a 16-bit operation, the TMJ1I interrupt requests of the TMJ-1 and
BUZZ outputs are effective. In case these functions are not necessary, make them invalid by
programming.
The TMJ-1 and TMJ-2, in combination, can be used for remote controlled data transmission.
Regarding the remote controlled data transmission, see section 14.3.3, Remote Controlled Data
Transmission.
14.3.2 8-bit Reload Timer (TMJ-2)
The TMJ-2 is an 8-bit down-counting reload timer. As the clock source, dividing clock, edge
signals through the
,54 pin or the underflow signals from the TMJ-1 are being used. By
selecting the edge signals through the
,54 pin, it can also be used as an event counter. While
it is working as an event counter, its reloading function is workable simultaneously.
When data are written into the reloading register TLK, these data will be written into the counter
TCK simultaneously. Also, when the counter TCK underflows, the data of the reloading register
TLK will be made to the data counter TCK.
When the counter underflows, TMJ2I interrupt requests will be issued.
The TMJ-2 and TMJ-1, in combination, can be used as a 16-bit reload timer. For more
information on the 16-bit reload timer, see section 14.3.1, 8-bit Reload Timer (TMJ-1).
The TMJ-2 and TMJ-1, in combination, can be operated by remote controlled data transmission.