
Analog Integrated Circuit Device Data
Freescale Semiconductor
15
33991
TIMING DESCRIPTIONS AND DIAGRAMS
COMMUNICATION MEMORY MAPS
1 = Nominal f=1MHz (for 8us calibration pulse)
PE3—Clock Calibration Enable—This bit enables or
disables the clock calibration.
0 = Disable
1 = Enable
PE2—Oscillator Adjustment
0 = T
OSC
1 = 0.66 x T
OSC
PE1— Gauge 1 Enable—This bit enables or disables the
output driver of Gauge 1.
0 = Disable
1 = Enable
PE0 —Gauge 0 Enable—This bit enables or disables the
output driver of Gauge 0.
0 = Disable
1 = Enable
MAXIMUM VELOCITY REGISTER (VELR)
SI Address 001—Gauge Maximum Velocity Register is
used to set a maximum velocity for each gauge. See Table 4.
Bits D7: D0 contain a position value from 1–255
representative of the table position value. The table value
becomes the maximum velocity until it is changed to another
value. If a maximum value is chosen greater than the
maximum velocity in the acceleration table, the maximum
table value will become the maximum velocity. If the motor is
turning at a value greater than the new maximum, the motor
will ignore the new value until the speed falls equal to, or
below it. Velocity for each motor can be changed
simultaneously, or independently, by writing D8 and/or D9 to
a logic [1]. Bits D10: D12 must be at logic [0] for valid VELR
commands.
These bits are
write-only
.
V12—V10 These bits must be transmitted as logic 0 for
valid VELR commands
V9—Gauge 1 Velocity—Specifies whether the maximum
velocity determined in the V7: V0 field will apply to Gauge 1.
0 = Velocity does not apply to Gauge 1
1 = Velocity applies to Gauge 1
V8 — Gauge 0 Velocity—Specifies whether the maximum
velocity specified in the V7: V0 field will apply to Gauge 0.
0 = Velocity does not apply to Gauge 0
1 = Velocity applies to Gauge 0
V7—V0 Maximum Velocity—Specifies the maximum
velocity position from the acceleration table. This velocity will
remain the maximum of the intended gauge until changed by
command.
Velocities can range from position 1 (00000001) to
position 255 (11111111).
GAUGE 0/1 POSITION REGISTER (POS0R, POS1R)
SI Addresses 010—Gauge 0 Position Register receives
writing when communicating the desired pointer positions.
SI Address 011—Gauge 1 Position Register receives
writing when communicating the desired pointer positions.
Register bits D11: D0 receives writing when
communicating the desired pointer positions.
Commanded positions can range from 0 to 4095. The D12
bit must be at logic [0] for valid POS0R and POS1R
commands.
These bits are
write-only
.
P0 12—This bit must be transmitted as logic[0] for valid
commands.
P0 11: P00—Desired pointer position of Gauge 0.
Pointer positions can range from 0 (000000000000) to
position 4095 (111111111111). For a stepper motor requiring
12 microsteps per degree of pointer movement, the
maximum pointer sweep is 341.25
°.
Table 7. Maximum Velocity Register (VELR)
Address: 001
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Write
0
0
0
V9
V8
V7
V6
V5
V4
V3
V2
V1
V0
Table 8. Gauge 0 Position Register (POS0R)
Address: 010
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Write
0
P011
P010
P09
P08
P07
P06
P05
P04
P03
P02
P01
P00
Table 9. Gauge 1 Position Register (POS1R)
Address: 011
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Write
0
P011
P010
P09
P08
P07
P06
P05
P04
P03
P02
P01
P00