Changes between Version 26 and Version 27 of MMC
- Timestamp:
- 12/16/2022 09:52:59 PM (2 years ago)
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MMC
v26 v27 328 328 === MicroSD bus 329 329 The initial SD bus speed of 12.5MB/s is the default mode defined by SD1.0. Later a 25MB/s High Speed Mode (HS) was defined by SD1.1. As higher performance levels were needed to support new and faster devices the SD association introduced faster bus interfaces: UHS-I, UHS-II, UHS-III, and SD Express. The bus speed is started with 25MHz SDR mode and depending on the capabilities of the host and device can negotiate to higher rates: 330 ||= Mode =||= Data Rate =||= Max Frequency =||= Max data rate at 8bit bus =||331 || Default Speed (DS) || Single || 25MHz || 12.5MB/s ||332 || High Speed (HS) || Single || 50MHz || 25MB/s ||333 || UHS-I DDR50 || Dual || 50MHz || 50MB/s ||334 || UHS-I SDR50 || Single || 100MHz || 50MB/s ||335 || UHS-I SDR104 || Single || 208MHz || 104MB/s ||330 ||= Mode =||= Voltage =||= Data Rate =||= Max Frequency =||= Max data rate at 8bit bus =|| 331 || Default Speed (DS) || 3.3V || Single || 25MHz || 12.5MB/s || 332 || High Speed (HS) || 3.3V || Single || 50MHz || 25MB/s || 333 || UHS-I DDR50 || 1.8V || Dual || 50MHz || 50MB/s || 334 || UHS-I SDR50 || 1.8V || Single || 100MHz || 50MB/s || 335 || UHS-I SDR104 || 1.8V || Single || 208MHz || 104MB/s || 336 336 * Note that UHS-I requires support for voltage switching I/O rail from 3.3V to 1.8V 337 337 * All modes start at DS and negotiate up if supported on both host and card