AMIS-30624 Datasheet, PDF (22/56 Pages) AMI SEMICONDUCTOR – I2C Microstepping Motordriver

AMIS-30624 I²C Microstepping Motordriver
Data Sheet
15.1.5. External Switch SWI
As illustrated in Figure 12, the SWI comparator is almost identical to HW. The major difference is in the limited number of states. Only
open or closed is recognised leading to respectively ESW = 0 and ESW = 1.
IÎ R
S_{PASS_T}
SWI S_TOP
S_BOT
DriveHS
DriveLS
LOGIC
State
Closed
Open
1 = R2GND 2 = R2VBAT 3 = OPEN
IÎ R
S_{PASS_B}
R_th
"R"-Comp
COMP
32 µs
Debouncer
SWI_Cmp
PC20060926.3
Figure 12: Simplified Schematic Diagram of the SWI Comparator
As illustrated in Figure 14, a change in state is always synchronized with DriveHS or DriveLS. The same synchronization is valid for
updating the internal position register. This means that after every current pulse (or closing of S_TOP or S_BOT) the state of position switch
together with the corresponding position is memorized.
Using the GetActualPos commands reads back the ActPos register and the status of ESW. In this way the master node may get
synchronous information about the state of the switch together with the position of the motor. See Figure 13.
Byte Content
0
Address
1
Address
2
Data 1
3
Data 2
4
Data 3
5
Data 4
6
Data 5
7
Data 6
8
Data 7
GetFullStatus1 Response Frame
Structure
Bit 7
Bit 6
Bit 5
Bit 4 Bit 3
1
1
OTP3 OTP2 OTP1
1
1
1
OTP3 OTP2
Irun[3:0]
Vmax[3:0]
AccShape StepMode[1:0] Shaft
VddReset StepLoss ElDef
UV2
TSD
Motion[2:0]
ESW OVC1
1
1
1
1
1
AbsThr[3:0]
Figure 13: GetFullStatus1 I²C Commando
Bit 2
Bit 1
Bit 0
OTP0
HW
1
OTP1 OTP0
HW
Ihold[3:0]
Vmin[3:0]
Acc[3:0]
TW
Tinfo[1:0]
OVC2 Stall CPFail
1
1
1
DelThr[3:0]
Important remark; Every 512µs this information is refreshed.
AMI Semiconductor – Apr. 2007, Rev 3.1, M-20664-003
22
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