Cinterion
®
Java Terminal Hardware Interface Description
8.4 Qualified Watchdog Configuration
90
PLS62T-W_HID_v01
2018-06-20
Confidential / Prelimenary
Page 76 of 91
8.4
Qualified Watchdog Configuration
While the complete watchdog functionality may be configured via TXD0 line of the ASC0 inter-
face (for details see
), a qualified set of configuration commands can also be spec-
ified via the watchdog‘s I
2
C interface as described in this section. The Java module has to be
up and running for this type of configuration.
The watchdogs‘s I
2
C interface is accessible by means of the Java module‘s I
2
C lines, and either
via the Java module‘s AT command interface, or through a Java MIDlet during runtime (see
Note:
When using a Java MIDlet to set GPIO directions using the I
2
C interface,
please allow for a guard time of at least 500ms between two I
2
C commands.
The I
2
C interface implements the write and the read protocol as described in
. The
7-bit device address is 0x6A (binary: 1101010). The default address can be changed by con-
figuration command (see
).
8.4.1
I
2
C Interface Command Specification
8.4.1.1
WRITE Command Syntax
Example setting the GPIO12 signal direction to “output” (see also section
):
Legend:
S: Start Condition, W: Write bit (=0), A: Acknowledge, P: Stop Condition.
8.4.1.2
READ Command Syntax
Example reading the last status = OK (see also section
Legend:
S: Start Condition, R: Read bit (=1), A: Acknowledge, N: Not Acknowledge, P: Stop Condition.
S
Slave address
(including write bit “W“)
A
Register address
A
Data byte
A
P
S
0xD4
(including write bit “0“)
A
0x14
A
0x01
A
P
S
Slave address
(including read bit “R“)
A
Register address
A
Data length
(only one byte)
N
P
S
0xD5
(including read bit “1“)
A
0x00
A
0x01
(only one byte)
N
P