STMicroelectronics /STM32L552 /SDMMC1 /SDMMC_CMDR

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Interpret as SDMMC_CMDR

31 2827 2423 2019 1615 1211 87 43 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0CMDINDEX0 (CMDTRANS)CMDTRANS 0 (CMDSTOP)CMDSTOP 0WAITRESP 0 (WAITINT)WAITINT 0 (WAITPEND)WAITPEND 0 (CPSMEN)CPSMEN 0 (DTHOLD)DTHOLD 0 (BOOTMODE)BOOTMODE 0 (BOOTEN)BOOTEN 0 (CMDSUSPEND)CMDSUSPEND

Description

The SDMMC_CMDR register contains the command index and command type bits. The command index is sent to a card as part of a command message. The command type bits control the command path state machine (CPSM).

Fields

CMDINDEX

Command index. This bit can only be written by firmware when CPSM is disabled (CPSMEN = 0). The command index is sent to the card as part of a command message.

CMDTRANS

The CPSM treats the command as a data transfer command, stops the interrupt period, and signals DataEnable to the DPSM This bit can only be written by firmware when CPSM is disabled (CPSMEN = 0). If this bit is set, the CPSM issues an end of interrupt period and issues DataEnable signal to the DPSM when the command is sent.

CMDSTOP

The CPSM treats the command as a Stop Transmission command and signals Abort to the DPSM. This bit can only be written by firmware when CPSM is disabled (CPSMEN = 0). If this bit is set, the CPSM issues the Abort signal to the DPSM when the command is sent.

WAITRESP

Wait for response bits. This bit can only be written by firmware when CPSM is disabled (CPSMEN = 0). They are used to configure whether the CPSM is to wait for a response, and if yes, which kind of response.

WAITINT

CPSM waits for interrupt request. If this bit is set, the CPSM disables command timeout and waits for an card interrupt request (Response). If this bit is cleared in the CPSM Wait state, will cause the abort of the interrupt mode.

WAITPEND

CPSM Waits for end of data transfer (CmdPend internal signal) from DPSM. This bit when set, the CPSM waits for the end of data transfer trigger before it starts sending a command. WAITPEND is only taken into account when DTMODE = MMC stream data transfer, WIDBUS = 1-bit wide bus mode, DPSMACT = 1 and DTDIR = from host to card.

CPSMEN

Command path state machine (CPSM) Enable bit This bit is written 1 by firmware, and cleared by hardware when the CPSM enters the Idle state. If this bit is set, the CPSM is enabled. When DTEN = 1, no command will be transfered nor boot procedure will be started. CPSMEN is cleared to 0.

DTHOLD

Hold new data block transmission and reception in the DPSM. If this bit is set, the DPSM will not move from the Wait_S state to the Send state or from the Wait_R state to the Receive state.

BOOTMODE

Select the boot mode procedure to be used. This bit can only be written by firmware when CPSM is disabled (CPSMEN = 0)

BOOTEN

Enable boot mode procedure.

CMDSUSPEND

The CPSM treats the command as a Suspend or Resume command and signals interrupt period start/end. This bit can only be written by firmware when CPSM is disabled (CPSMEN = 0). CMDSUSPEND = 1 and CMDTRANS = 0 Suspend command, start interrupt period when response bit BS=0. CMDSUSPEND = 1 and CMDTRANS = 1 Resume command with data, end interrupt period when response bit DF=1.

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