S32CT Clocks Info

Look up what and how the clock tree of a specific (MCU, RTD, package) combination can be configured in the S32 Configuration Tools Clocks tool, by parsing the XML data model shipped with the installed Real-Time Drivers / Platform SDK. Read-only - answers questions about clock sources, PLLs, dividers, selectors, gates, peripheral clock outputs, register writes and power modes. Companion of s32ct-pins-info and s32ct-peripherals-info for the Clocks tool.

When to use

• Use for: enumerating available clock sources, dividers, selectors, gates, fractional dividers, peripheral clock outputs; discovering the configurable attributes and legal values of a clock module; locating the register / bit-field that the Clocks tool writes for a given choice; mapping clock_source -> selector -> divider -> gate -> peripheral_clock_output; diagnosing why a setting is missing; authoring or validating the <clocks> block of a .mex.
• Do not use this skill for: modifying a .mex (use s32ct-clocks-graft-mex, s32ct-generate-mex-config, or the Clocks CLI); generating Clock_Ip_Cfg.[ch] driver code (use s32ct-generate-code with tool_name="Clocks"); pin or peripheral queries (use s32ct-pins-info / s32ct-peripherals-info).

Available Capabilities

This skill is read-only. The capabilities below only inspect the Clocks data model; none of them modify a .mex, generate code, or execute a CLI.

Type	Name	Invocation
Query	Clock-tree overview	mcu="S32K312", package="S32K312_172HDQFP"
Query	Resolve a clock point / frequency	query="CAN_PE_CLK"
Reference	Full XML anatomy and filter schema	references/clock-inspection.md
Reference	Worked query examples	references/examples.md
Data	<S32DS>/eclipse/mcu_data/processors/<mcu>/<platform_sdk>/clocks/<package>/	The per-package XML data model consumed by this skill.

Post 16->5 tool mapping

Write-side and CLI actions belong to the sibling skills listed below. They are documented here only so the agent knows where to hand off - this skill never invokes them.

Sibling skill id	MCP call to use
s32ct-cli	nxp_s32ct_execute_action(action_name="s32ct.configure_cli", params={...})
s32ct-clocks-facade	nxp_s32ct_execute_action(action_name="s32ct.configure_clocks", params={...})
s32ct-generate-code	nxp_s32ct_execute_action(action_name="s32ct.generate_code", params={...})

Quickstart

1. Resolve paths from mcu, package, and platform_sdk (defaults to the sole subfolder under mcu_data/processors/<mcu>/ when exactly one exists):

   <S32DS_INSTALL>/eclipse/mcu_data/processors/<mcu>/<platform_sdk>/clocks/<package>/
   

2. Overview of the data model for a package:

   { "mcu": "S32K312", "package": "S32K312_172HDQFP",
     "include_register_writes": false }
   

   Returns the discovered XML files, clock sources, output-signal counts, power modes, and top-level <configuration_element> entries.

3. Modes and register writes for one module:

   { "mcu": "S32K312", "package": "S32K312_172HDQFP",
     "filter": { "module": "FXOSC" } }
   

4. What feeds a peripheral clock:

   { "mcu": "S32K312", "package": "S32K312_172HDQFP",
     "filter": { "output": "LPUART2_CLK" } }
   

5. Lookup by register bit-field:

   { "mcu": "S32K312", "package": "S32K312_172HDQFP",
     "filter": { "register": "FXOSC::CTRL", "bit_field": "OSCON" } }
   

More payloads in references/examples.md. Enumeration internals and the XML/.mex mapping are in references/clock-inspection.md.

Configuration

Name	Type	Required	Description
mcu	string	yes	Folder name under mcu_data/processors/. Case-sensitive.
package	string	yes	Folder name under clocks/. Case-sensitive.
platform_sdk	string	no	Defaults to the sole subfolder when exactly one exists.
s32ds_install	string	no	Override of the S32CT install root. MCP auto-discovers desktop or integrated_s32ds at startup - see s32ct-distributions.
query	string	no	Free-form question, fuzzy-matched.
filter	object	no	Structured filter (see references/clock-inspection.md). AND-combined.
include_register_writes	bool	no	Default true. Include <assign register="..." bit_field="..."/> rows.
include_constraints	bool	no	Default true. Include <constraint> / <enable> rules.
max_results	int	no	Default 200.

Guardrails

Scope. Reads files only from <S32DS_INSTALL>/eclipse/mcu_data/.../clocks/<package>/. Does not modify any project, .mex, target memory, or system state. Idempotent and safe to call multiple times.

Destructive actions. None. Purely read-only.

Refuse-and-escalate. Refuses when required MCU/SDK/package directories are missing, when the clocks directory contains no XML, or when a filter references an unknown key - returns an actionable error listing available alternatives. Never invents <configuration_element> ids, <item> values, register names, or bit-field names; quotes only what is present in the XML.

Validation loop

1. Resolve mcu -> platform_sdk -> package paths and confirm each directory exists. On failure, return the error template listing available subfolders (s32ct-clocks-info never raises).
2. Discover .xml files by listing the clocks directory. Ignore .dsn (binary GUI diagram) and other non-XML assets.
3. Parse each .xml. The root may be <clocks:top_level>, <clocks:component>, or <clocks:power_modes> - strip the clocks: prefix before iterating, otherwise namespace matching silently skips every child.
4. Build the in-memory index keyed by module id, <clock_source id>, <output_clock_signal id>, <input_clock_signal id>, <configuration_element id>, <power_mode id>, and every <assign register bit_field/>.
5. Apply filter (indexed fast path) and/or query (fuzzy fallback); walk matched nodes and emit verbatim XML excerpts. Never paraphrase attribute values.
6. Pass = every filter key resolves and the answer includes verbatim <configuration_element> / <assign> / <clock_source> / <map_output> / <power_mode> / <constraint> evidence, capped at max_results with a truncation note when needed. Fail = any filter key is unknown or matches nothing - return the "closest matches" error.

Out of scope

• Modifying .mex files, driver sources, or any installed tooling.
• Pin-tool and Peripherals-tool queries (use s32ct-pins-info / s32ct-peripherals-info).
• Executing code on target hardware or reading target memory.
• Parsing .dsn GUI vector diagrams for authoring data.
• Guessing values not present in the XML - RTD versions and MCUs diverge, only the XML is authoritative.

See Also

• references/clock-inspection.md - the XML data-model layout (TOP.xml, FXOSC.xml, SXOSC.xml, MODULE_CLOCKS.xml, POWER_MODES.xml), schema element table, filter schema, output format, behaviour rules, the exact XML <-> .mex mapping used when authoring the <clocks> block, the pre-insertion checklist, hand-off chain, and full error-message templates.
• references/examples.md - worked example payloads for the five most common query patterns (package overview, single-module details, peripheral-clock trace, register-bit lookup, power modes).
• Related skills: s32ct-pins-info (Pins-tool data model), s32ct-peripherals-info (Peripherals-tool data model), s32ct-clocks-graft-mex (write-side: apply presets / tweak / lift), s32ct-generate-mex-config (bake settings into a .mex), s32ct-generate-code (tool_name="Clocks" - emit Clock_Ip_Cfg.[ch] and Clock_Ip_Cfg_Defines.h), s32ct-distributions (install-root discovery).