Renesas Hitachi H8S/2191, Hardware Manual

Page: 375 / 1065

Rev. 2.0, 11/00, page 348 of 1037
(4) In case the acceleration has not been finished (in case the CFG signal is not input even when
the prescribed time has elapsed = underflowing of down-counting has occurred), such
underflowing works to set to CFG mask F/F (masking movement) and the reload timer will
be cleared by the CFG.
(5) When the acceleration has been finished (when the CFG signal is input before the prescribed
time has elapsed = reloading movement has been made before the down counter underflows),
an interrupt request will be issued because of the CFG.
When making breaking:
(1) Set the AC/BR bit of the TMRM1 to braking. (Clear to 0). Also, use the rising edge of the
CFG as the reloading signal.
(2) Set the prescribed time on the CFG frequency to deem as the braking has been finished, into
the reloading register.
(3) The TMRU-2 will work to down-count the reloading data.
(4) In case the braking has not been finished (when the CFG signal is input before the prescribed
time has elapsed = reloading movement has been made before the down counter underflows),
the reload timer movement will continue.
(5) When the acceleration has been finished (when the CFG signal is not input even when the
prescribed time has elapsed = underflowing of down-counting has occurred), interrupt
request will be issued because of the underflowing signal.
The acceleration and braking processes should be employed when making special reproductions,
in combination with the slow tracking mono-multi function being outlined below.
For exemplary settings for the register, see section 16.5.4, Acceleration and Braking Processes
of the Capstan Motor.
16.3.7 Slow Tracking Mono-multi Function
When performing slow reproductions or still reproductions, the braking timing for the capstan
motor is determined by use of the edge of the DVCTL signal. The slow tracking mono-multi
function works to measure the time from the rising edge of the DVCTL signal down to the
desired point to issue the interrupt request. In actual programming, this interrupt should be used
to activate the brake of the capstan motor. The TMRU-3 should be used to perform time
measurements for the slow tracking mono-multi function. Also, the braking process can be
made using the TMRU-2. Figure 16.2 below shows the exemplary time series movements when
a slow reproduction is being performed.
For exemplary settings for the register, see section 16.5.3, Slow Tracking Mono-multi Function.