Component - Status Register V1.80 Datasheet.pdf

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PSoC Creator™ Component Datasheet
Status Register
1.80
Features
 Up to 8-bit Status Register
 Interrupt support
General Description
The Status Register allows the firmware to read digital signals.
When to Use a Status Register
Use the Status Register when the firmware needs to query the state of internal digital signals.
Input/Output Connections
This section describes the input connections for the status register. An asterisk (*) in the list of
I/Os indicates that the I/O may be hidden on the symbol under the conditions listed in the
description of that I/O.
clock – Input
Status register clock. The clock input signal is ignored for bits configured as Transparent.
status_0 - status_7 – Input *
Status register input. The firmware queries the input signals by reading the status register. The
number of inputs depends on the Inputs parameter. These inputs may be left floating with no
external connection. If nothing is connected to these lines, the component will assign a constant
logic 0.
status[N:0] – Input *
This optional input sweeps the individual input terminals into a single bus terminal. This pin is
visible when the Display as bus parameter is enabled. N is the number of inputs - 1. This input
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Document Number: 001-85018 Rev. *A
Revised February 20, 2013
Status Register
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PSoC Creator™ Component Datasheet
may be left floating with no external connection. If nothing is connected to this line, the
component will assign a constant logic 0.
intr – Output *
This optional pin is shown on the symbol when the Generate interrupt parameter is enabled.
This option is only valid if less than 8 inputs are selected.
Component Parameters
Drag a Status Register onto your design and double-click it to open the Configure dialog.
Inputs
Number of input terminals (1 to 8). The default value is 8.
Display as bus
This parameter displays the input as a bus instead of individual terminals. This option is
unchecked by default.
Generate interrupt
This parameter displays the interrupt input on the symbol. This option is unchecked by default.
Interrupt is valid only if the number of inputs is less than 8.
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PSoC Creator™ Component Datasheet
Status Register
Set all modes
This button sets all bits to either Transparent or Sticky mode, depending on the mode selected
in the combo box in the left hand side of this button.
Mode
These parameters are used to set specific bits of the Status Register to be held high after being
registered, until a read is executed. That read clears all registered values. The settings are:

Transparent – By default, a CPU read of this register transparently reads the state of the
associated routing net and is asynchronous to the block clock. This mode can be used for
transient state that is computed and registered internally in the UDB.

Sticky (Clear on Read) – In this mode, the associated routing net is sampled on each cycle
of the status and control clock. If the signal is high in a given sample, it is captured in the
status bit and remains high, regardless of the subsequent state of the associated route.
When CPU firmware reads the status register, the bit is cleared. The status register clearing
is independent of mode and will occur even if the block clock is disabled; it is based on the
bus clock and occurs as part of the read operation.
Figure 1. Behavior of Transparent versus Sticky Modes
Interrupt mask
This option is shown in the configure dialog only when Generate interrupt is checked. These
parameters allow to set the interrupt mask value for each bit in the Status Register. By default,
the interrupt mask value is 0.
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Status Register
PSoC Creator™ Component Datasheet
Application Programming Interface
Application Programming Interface (API) routines allow you to configure the component using
software.
By default, PSoC Creator assigns the instance name “Status_Reg_1” to the first instance of a
status register in any given design. You can rename the component to any unique value that
follows the syntactic rules for identifiers. The instance name becomes the prefix of every global
function name, variable, and constant symbol. For readability, the instance name used in the
following function is “StatusReg.”
Function
Description
StatusReg_Read()
Reads the current value of the status register
StatusReg_InterruptEnable()
Enables the status register interrupt
StatusReg_InterruptDisable()
Disables the status register interrupt
StatusReg_WriteMask()
Writes the value assigned to the mask register
StatusReg_ReadMask()
Returns the current interrupt mask value from the mask register
uint8 StatusReg_Read (void)
Description:
Reads the value of a status register.
Parameters:
None
Return Value:
Returns the current value of a status register.
Side Effects:
None
void StatusReg_InterruptEnable (void)
Description:
Enables the status register interrupt. The default behavior is disabled. This is only valid if the
status register generates an interrupt.
Parameters:
None.
Return Value:
None.
Side Effects:
None.
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PSoC Creator™ Component Datasheet
Status Register
void StatusReg_InterruptDisable (void)
Description:
Disables the status register interrupt. This is only valid if the status register generates an
interrupt.
Parameters:
None.
Return Value:
None.
Side Effects:
None.
void StatusReg_WriteMask (uint8 mask)
Description:
Writes the current mask value assigned to the status register. This is only valid if the status
register generates an interrupt.
Parameters:
mask: The value to write into the mask register.
Return Value:
None.
Side Effects:
None.
uint8 StatusReg_ReadMask (void)
Description:
Reads the current interrupt mask value assigned for the status register. This is only valid if the
status register generates an interrupt.
Parameters:
None.
Return Value:
Returns the current value of the interrupt mask.
Side Effects:
None
DMA
The DMA component can be used to read data directly from Status Register. The DMA Wizard
can be used to configure DMA operations as follows:
Name of DMA
Source/Destination in DMA
Wizard
StatusReg_Status_PTR
Direction
Source
DMA Req
Signal
DMA Req
Type
N/A
N/A
Description
Stores Status Register value.
MISRA Compliance
This section describes the MISRA-C:2004 compliance and deviations for the component. There
are two types of deviations defined:

project deviations – deviations that are applicable for all PSoC Creator components
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Status Register

PSoC Creator™ Component Datasheet
specific deviations – deviations that are applicable only for this component
This section provides information on component-specific deviations. Project deviations are
described in the MISRA Compliance section of the System Reference Guide along with
information on the MISRA compliance verification environment.
The Status Register component does not have any specific deviations.
Sample Firmware Source Code
PSoC Creator provides numerous example projects that include schematics and example code
in the Find Example Project dialog. For component-specific examples, open the dialog from the
Component Catalog or an instance of the component in a schematic. For general examples,
open the dialog from the Start Page or File menu. As needed, use the Filter Options in the
dialog to narrow the list of projects available to select.
Refer to the “Find Example Project” topic in the PSoC Creator Help for more information.
Resources
The Status Register component uses one status cell in the UDB array.
API Memory Usage
The component memory usage varies significantly, depending on the compiler, device, number
of APIs used and component configuration. The following table provides the memory usage for
all APIs available in the given component configuration.
The measurements have been done with the associated compiler configured in Release mode
with optimization set for Size. For a specific design the map file generated by the compiler can
be analyzed to determine the memory usage.
PSoC 3 (Keil_PK51)
Configuration
Default
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PSoC 4 (GCC)
PSoC 5LP (GCC)
Flash
RAM
Flash
RAM
Flash
RAM
(Bytes)
(Bytes)
(Bytes)
(Bytes)
(Bytes)
(Bytes)
46
0
92
0
92
0
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PSoC Creator™ Component Datasheet
Status Register
Component Changes
This section lists the major changes in the component from the previous version.
Version
Description of Changes
1.80a
Updated datasheet with memory usage for
PSoC 4.
1.80
Added MISRA Compliance section.
1.70
Added PSoC 5LP support.
Reason for Changes / Impact
The component does not have any specific deviations.
Implemented StatusReg_InterruptEnable(),
StatusReg_InterruptDisable(),
StatusReg_WriteMask() and
StatusReg_ReadMask() APIs.
To support interrupt functionality.
Updated the Configure dialog.
Added Display as bus, Generate interrupt, Set all modes,
Interrupt mask parameters and minor design changes.
Added interrupt pin and display as bus option
for input terminals. Also implemented DMA
capabilities and Debug window support.
To have input terminals as bus and to support interrupt
generation.
1.60
Updated the Configure dialog
Changed the Bit display and addressed minor Configure
dialog issues
1.50.b
Datasheet edits
1.50.a
Datasheet edits
1.50
Updated the Configure dialog.
Created a customized interface. Added "Set All" buttons
and changed Number of Inputs field to allow keyboard
entry. Updated the dialog to comply with corporate
standards.
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Document Number: 001-85018 Rev. *A
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