Toshiba TLCS-90 Series Data Book page 305

TOSHIBA TMP90C840
The 4-phase 1-2 step excitation is obtained as follows:
Given the Port bits
I
b7 b6 b5 b4 b3 b2 bl bO
I
initialially
arranged as
I
b3 b7 b2 b6 bl b5 bO b2
I,
set three succeeding
bits to "1", and the other bits to "0" (Positive logic).
For example, initializing b3, b7 and b2 to "1" provides the initial
value "10001100", which produces the waveforms in Fig. 3.7 (8).
To obtain the negative logic output, the above initial value of Port 6
should be inverted.
That is, the waveforms in Fig. 3.7 (8) can be converted to the
negative logic output by initializing the P6 bits to "011110011".
When Channel 0 is selected, for example, the stepping morot control
port is controlled as follows:
The output latch of MO (also used as P6) and the stepping motor
control shifter alternate register (SA6) rotate at the rising edge of
the TFF 1 trigger pu lse and are output to the port. The rot at ing
direction is selected by SMCRO (CCW6).
Fig. 3.7 (9) is a block diagram of this excitation.
output
Sifter Alternate
Latch
Register
b3
M03 (P63)
Jl..
SL
b2
H
M02(P62)
::l
rt
(i)
Ii
SL
::l
III
I-'
11
0
III
rt
bl
III
MOl (P61)
to
C
en
.fL
SL
bO
MOO(P60)
Jl
Fig. 3.7 (9) Block Diagram of
4~phase
1-2 step Excitation
(Normal Rotation)
MPU90-107