TMC223 DATASHEET (V. 1.05 / March 7, 2011)
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Every byte put on the SDA line must have a length of 8 bits, where the most significant bit (MSB) is
transferred first. The number of bytes that can be transmitted to the TCM222 is restricted to 8 bytes.
Each byte is followed by an acknowledge bit, which is issued by the receiving node (see figure below).
MSB
1
ACK
9
ACK
9
SDA
SCL
2
7
8
1
STOP
condition
START
condition
Figure 17: Two Wire Serial Interface - Data Transfer
6.3 Physical Address of the circuit
The circuit must be provided with a physical address in order to discriminate this circuit from other
ones on the serial bus. This address is coded on seven bits (two bits are internally hardwired to ‘1’),
yielding the theoretical possibility of 32 different circuits on the same bus. It is a combination of four
OTP memory bits (see Table 9: OTP Memory Structure) and one hardwired address bit (pin HW). HW
must either be connected to ground or Vbat. When HW is not connected and left floating correct
functionality of the serial interface is not guaranteed. Pin HW uses the same principle to check whether
it is connected to ground or Vbat like the SWI input (see 5.1.9 External Switch).
The TMC223 supports a “general call” address. Therefore the circuit is addressable using either the
physical slave address or address “000 0000”.
AD6
'1'
AD5
'1'
AD4
AD3
AD2
AD1
AD0
Physical address
OTP Memory
OTP_AD3 OTP_AD2OTP_AD1 OTP_AD0
Hardwired Bit
(Connect to 0 or 1)
HW2
Figure 18: Two Wire Serial Interface - Physical Address resp. Address Field
With un-programmed OTP address bits (OTP_AD3=o, OTP_AD2=o, OTP_AD1=o, OTP_AD0=o) and
HW='0' (pin HW @ GND), the slave address resp. the address field of the TMC223 for reading is
11oooo01 (0xC1, 193) and for writing the slave address resp. the address field is 11oooo00 (0xC0,
192). The LSB of the address field selects read (='1') and write (='0'). With un-programmed OTP
address bits and HW='1' (pin HW @ Vbat), the slave address resp. the address field of the TMC223
for reading is 11oooo11 (0xC3, 195) and for writing the salve address resp. the address field is
11oooo10 (0xC2, 194).
Important Hint: The HW is not a logic level input as usual; it needs to be connected via 1K resistor
either to +VBAT or GND;
6.4 Write data to TMC223
A complete datagram consists of the following: a Start condition, the slave address (7 bit), a read/write
bit (‘0’ = write, ‘1’ = read), an acknowledge bit, a number of data bytes (8 bit) each followed by an
acknowledge bit, and a Stop condition. The acknowledge bit is used to signal to the transmitter the
correct reception of the preceding byte, in this case the TMC223 pulls the SDA line low.
The TMC223 reads the incoming data at SDA with every rising edge of the SCL line. To finish the
transmission the master has to transmit a Stop condition. Some commands for the TMC223 are
supporting eight bytes of data, other commands are transmitting two bytes of data.
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