serve as glue logic between the device and external devices. This increases the reliability of the PCB by
reducing its complexity, and enables more powerful functions.
40.6.2. Basic Operation
40.6.2.1. Initialization
The following bits are enable-protected, meaning that they can only be written when the corresponding
even LUT is disabled (LUTCTRL2x.ENABLE=0):
•
Sequential Selection in Sequential Control x register (SEQCTRLx.SEQSEL)
The following registers are enable-protected, meaning that they can only be written when the
corresponding LUT is disabled (LUTCTRLx.ENABLE=0):
•
LUT Control x register, except ENABLE bit (LUTCTRLx)
Enable-protected bits in the LUTCTRLx registers can be written at the same time as LUTCTRLx.ENABLE
is written to '1', but not at the same time as LUTCTRLx.ENABLE is written to '0'.
Enable-protection is denoted by the Enable-Protected property in the register description.
40.6.2.2. Enabling, Disabling, and Resetting
The CCL is enabled by writing a '1' to the Enable bit in the Control register (CTRL.ENABLE). The CCL is
disabled by writing a '0' to CTRL.ENABLE.
Each LUT is enabled by writing a '1' to the Enable bit in the LUT Control x register (LUTCTRLx.ENABLE).
Each LUT is disabled by writing a '0' to LUTCTRLx.ENABLE.
The CCL is reset by writing a '1' to the Software Reset bit in the Control register (CTRL.SWRST). All
registers in the CCL will be reset to their initial state, and the CCL will be disabled. Refer to
for
details.
40.6.2.3. Lookup Table Logic
The lookup table in each LUT unit can generate any logic expression OUT as a function of three inputs
(IN[2:0]), as shown in
. One or more inputs can be masked. The truth table for the expression
is defined by TRUTH bits in LUT Control x register (LUTCTRLx.TRUTH).
Figure 40-2. Truth Table Output Value Selection
TRUTH[0]
TRUTH[1]
TRUTH[2]
TRUTH[3]
TRUTH[4]
TRUTH[5]
TRUTH[6]
TRUTH[7]
OUT
IN[2:0]
LUTCTRL
(ENABLE)
LUT
Table 40-1. Truth Table of LUT
IN[2]
IN[1]
IN[0]
OUT
0
0
0
TRUTH[0]
0
0
1
TRUTH[1]
0
1
0
TRUTH[2]
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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