AMIS-30624 Datasheet, PDF (43/56 Pages) AMI SEMICONDUCTOR – I2C Microstepping Motordriver

AMIS-30624 I²C Microstepping Motordriver
Data Sheet
16.6.1. Data Transfer Formats
16.6.1.1. Writing Data to AMIS-30624
When writing to AMIS-30624, the master-transmitter transmits to slave-receiver and the transfer direction is not changed. A complete
transmission consists of:
• Start condition
• The slave address (7-bit)
• Read/Write bit (‘0’ = write)
• Acknowledge bit
• Any further data bytes are followed by an acknowledge bit. The acknowledge bit is used to signal a correct reception of the
data to the transmitter. In this case the AMIS-30624 pulls the SDA line to ‘0’. The AMIS-30624 reads the incoming data at SDA
on every rising edge of the SCK signal
• Stop condition to finish the transmission
S Slave Address R/W A
Data
A
Data
AP
"0" = WRITE
N bytes + Acknowledge
Master to AMIS-30624
AMIS-30624 to Master
S = Start condition
P = Stop condition
A = Acknowledge (SDA = LOW)
A = No Acknowledge (SDA = HIGH)
PC20070219.3
Figure 30: Master Writing Data to AMIS-30624
Some commands for the AMIS-30624 are supporting eight bytes of data, other commands are transmitting two bytes of data.
See Table 30.
16.6.1.2. Reading Data from AMIS-30624
When reading data from AMIS-30624 two transmissions are needed:
1) The first transmission consists of two bytes of data:
• The first byte contains the slave address and the write bit.
• The second byte contains the address of an internal register in the AMIS-30624. This internal register address is stored in the
circuit RAM.
S Slave Address R/W A Internal Address A P
"0" = WRITE
PC20070219.5
Figure 31: Master Reading Data from AMIS-30624: First Transmission is Addressing
2) The second transmission consists of the slave address and the read bit. Then the master can read the data bits on the SDA line on
every rising edge of signal SCK. After each byte of data the master has to acknowledge correct data reception by pulling SDA LOW.
The last byte is not acknowledged by the master and therefore the slave knows the end of transmission.
S Slave Address R/W A
Data
A
Data
AP
"0" = WRITE
N bytes + Acknowledge
Master to AMIS-30624
AMIS-30624 to Master
S = Start condition
P = Stop condition
A = Acknowledge (SDA = LOW)
A = No Acknowledge (SDA = HIGH)
PC20070219.3
Figure 32: Master Reading Data from AMIS-30624: Second Transmission is Reading Data
Notes:
(1) Each byte is followed by an acknowledgment bit as indicated by the A or Ā in the sequence.
AMI Semiconductor – Apr. 2007, Rev 3.1, M-20664-003
43
www.amis.com