50.2. EEPROM Emulation Performance Test

50.2.1. Overview

This example tests the performance of the EEPROM emulation component. It evaluates efficiency through large numbers of read/write and defragmentation operations, and reports timing for config (init), write, flush, read, and delete.

50.2.2. Test Parameters

Default configuration (modify in main.c):

Macro	Description
DEMO_TEST_VAR_CNT	Number of test variables (default 50)
DEMO_WRITE_CYCLE	Write/update cycles per variable (default 5)
DEMO_ERASE_SIZE	Flash erase unit size in bytes (default 4096)
DEMO_SECTOR_CNT	Sector count, must be even (default 32)

Total writes in write performance test = DEMO_TEST_VAR_CNT × DEMO_WRITE_CYCLE (e.g. 250).

50.2.3. Performance Metrics

The example measures the following:

Configuration (init) time
- Clear storage, then measure e2p_config() execution time
- Includes header verification, state recovery, index table rebuild
Write performance
- Clear and init, then write all test variables (each updated DEMO_WRITE_CYCLE times)
- Report total time and average time per write
Flush (defragmentation) performance
- Clear, init, write test data, then measure e2p_flush(E2P_FLUSH_FORCE) time
- Includes state switching, data copy to backup area, old area erase
Read performance
- Clear, init, write test data, then measure total time to read all variables
- Report total time and average time per read (includes CRC32 verification)
Delete performance
- Clear, init, write test data, then measure total time to delete all variables
- Delete only marks entries invalid; space is reclaimed on next flush

50.2.4. Usage

After the example starts, choose a test via serial input:

========================================
  EEPROM Emulation Perf Test
========================================
  1 - Test config/init time
  2 - Test write performance
  3 - Test flush performance
  4 - Test read performance
  5 - Test delete performance
  6 - Show status info
  i - Show this menu
========================================

Test operations:

Press 1 — Test initialization (config) performance
Press 2 — Test write performance
Press 3 — Test defragmentation (flush) performance
Press 4 — Test read performance
Press 5 — Test delete performance
Press 6 — Show current status info

50.2.5. Output Examples

Config (init) performance:

=== Test: Configuration (Init) ===
[E2P INFO] ------------ e2p init ok -----------
[E2P INFO] start address : 0x80fd0000
[E2P INFO] sector count  : 16
[E2P INFO] erase size    : 4096
[E2P INFO] version       : 0x4553
[E2P INFO] end address   : 0x80fe0000
[E2P INFO] data_ptr=0x80fd0000  info_ptr=0x80fdffa4  remain=0xffa4
[E2P INFO] entries valid / total : 0 / 0
[E2P INFO] ------------------------------------
  Config time: 32451 us

Write performance:

=== Test: Write Performance ===
Writing 50 variables, 5 updates each...
Write completed: 50 variables x 5 updates = 250 total writes
  Total writes: 250
  Total time: 123456 us
  Avg per write: 493 us

Flush performance:

=== Test: Flush Performance ===
Writing 50 variables, 5 updates each...
Write completed: 50 variables x 5 updates = 250 total writes
  Flush time: 346190 us

Read performance:

=== Test: Read Performance ===
  Success reads: 50 / 50
  Total time: 1450 us
  Avg per read: 29 us

Delete performance:

=== Test: Delete Performance ===
  Success deletes: 50 / 50
  Total time: 890 us
  Avg per delete: 17 us

50.2.6. Notes

Item	Suggestion
erase_size	Larger erase blocks increase flush time. Choose 4KB–64KB based on data size.
sector_cnt	Must be even. More sectors reduce flush frequency but increase init/scan time.
Single entry size	Keep single write ≤ E2P_FLUSH_BUF_SIZE (user_config.h).
Critical section	Keep E2P_CRITICAL_ENTER/EXIT scope minimal; avoid long operations inside.