User manual

AHHYTM_E2.2.1
16/23
Application Note
Humidity Module
HYT
At writing access both command data bytes contains the data, at reading access both data bytes must be set to
0x00. The response to the command-mode message can be read out by a Data-Fetch. The response time of the
command-mode messages are 100 µs.
Table 2 shows the response to the start of the command-mode.
S 6 5 4 3 2 1 0 R A 7 6 5 4 3 2 1 0 N P
S 0 1 0 1 0 0 0 0 A S S D D D D R R N P
Slave Address Status Diagnostics Response
Table 2
Status: 10b command-Mode
01b stale
Diagnostic: xxx1b corrected EEPROM-error
xx1xb uncorrectable EEPROM-error
x1xxb RAM Parity error
1xxxb conguration error
Response: 00b busy
01b positive acknowledge
10b negative acknowledge
Table 3 shows the response to the read out of the I
2
C-address.
S 6 5 4 3 2 1 0 R A 7 6 5 4 3 2 1 0 A 7 6 5 4 3 2 1 0 A 7 6 5 4 3 2 1 0 A P
S 0 1 0 1 0 0 0 0 A S S D D D D R R A E E E E E E E E A E E E E E E E E A P
Slave Address Status Diagnostics Response EEPROM Data (15:8) EEPROM Data (7:0)
Table 3
Status: see table 2 on page 16
Diagnostic: see table 2 on page 16
Response: see table 2 on page 16
EEPROM-Data: content of the memory
The response to the command byte 0x1C contains the I
2
C-address in bitposition 6:0, default value is 0101000b. The
old I
2
C-address is valid until the module is in command mode.
The following table shows a complete process of reading and writing back of the I
2
C-address.
Power – On Reset
S 0x50 A 0xA0 A 0x00 A 0x00 N P Start Command – Mode
S 0x51 A 0x81 N P Response (ACK)
S 0x50 A 0x1C A 0x00 A 0x00 N P Read out Data Bytes with I
2
C-address
S 0x51 A 0x81 A Highbyte A Lowbyte N P Response
Write the new address into the bits 6:0 of the lowbyte.
S 0x50 A 0x5C A Highbyte A Lowbyte N P Write back Data Bytes with I
2
C-address
S 0x51 A 0x81 N P Reponse (ACK)