ATA5279_10 ATMEL [ATMEL Corporation], ATA5279_10 Datasheet - Page 9

• Manufacturer Part Number: ATA5279_10
• Description: Antenna Driver for Multiple Antennas
• Manufacturer: ATMEL [ATMEL Corporation]

3.6.1
9125I–RKE–09/10
Functional Description of Diagnosis Mode
In this diagnosis mode, the coil-line drivers themselves are switched to high impedance.
Hence, only the test structure at every coil connection (both at the positive outputs AxP of the
drivers and at the negative outputs AxN) is present and can directly test the status of the line.
Figure 3-3
Figure 3-3.
The structure above can be found in each of the six channels of the Atmel
as the diagnosis mode is engaged, all channels are operated in this way. On the channel that
is actually selected, the setting of the switches can be changed with the Set Coil Current com-
mand and the status of the two connection lines can be checked with the Get Driver Setup
command.
The two switches in the P line driver are controlled with one bit. That means, either the
high-side (S_HxP) or the low-side (S_LxP) switch is closed. The same is true for the N line
driver (S_HxN, S_LxN). The controlling bits c
register (see
Note that the setting of the switches is latched. That means, if the setting on the switches of
the selected driver is changed, the setting on the five other channels remains unchanged.
By a combination of test structures, many different faults, even between the coils, can be
detected.
As described in the principle schematic of a driver stage above, a test structure consists of two
switchable current sources (one to VDS and one to GND) and a comparator that converts the
voltage level on the line into a digital signal. The switches for the current sources can only be
controlled in diagnosis mode, with the corresponding coil being selected (see also Driver
Command description). Note that one switch is always closed, either the high-side or the
low-side switch of one test structure. These structures are independent, i.e., they can be set
up for each line individually and at the same time.
The status of the connection lines of the selected coil can be read out with a SPI command.
c0 bit
illustrates this:
Section 3.9.2 “General Command Description” on page 21
Base Structure of the Diagnosis Module of One Output Channel
VDS
AGND
S_HxP
c0 = '1'
c0 = '0'
S_LxP
AxP
c0, 1 bits
Latch
0
and c
1
are taken from the coil current selection
AxN
Driver x select
S_HxN
c1 = '1'
c1 = '0'
S_LxN
AGND
Atmel ATA5279
VDS
in this document).
®
ATA5279. As soon
c1 bit
9