SPRUJ42 User guide

SPRUJ42E March 2022 – October 2024 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1

PRODUCTION DATA

5.15.2.26 MMC_CAPA2 Register

15.2.26.1 MMC_CAPA2 Register (Offset = 244h) [reset = 0h]

Capabilities 2 Register

This register provides the Host Driver with information specific to the Host Controller implementation. The Host Controller may implement these values as fixed or loaded from flash memory during power on initialization. Refer to Software Reset For All in the Software Reset register for loading from flash memory and completion timing control.

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Table 5-1814 Instance Table

Instance Name	Physical Address
MMCSD0	4830 0244h

Figure 5-895 MMC_CAPA2 Name Register

31	30	29	28	27	26	25	24
RESERVED3
R
0h
23	22	21	20	19	18	17	16
CM
R
0h
15	14	13	12	11	10	9	8
RTM		TSDR50	RESERVED2	TCRT
R		R	R	R
0h		0h	0h	0h
7	6	5	4	3	2	1	0
RESERVED1	DTD	DTC	DTA	RESERVED	DDR50	SDR104	SDR50
R	R	R	R	R	R	R	R
0h	0h	0h	0h	0h	0h	0h	0h

Table 5-1815 MMC_CAPA2 Register Field Descriptions

Bit	Field	Type	Reset	Description
31:24	RESERVED3	R	0h
23:16	CM	R	0h	Clock Multiplier This field indicates clock multiplier value of programmable clock generator. Refer to Clock Control register. Setting 00hmeans that Host Controller does not support programmable clock generator. 00h: Clock Multiplier is Not Supported 01h: Clock Multiplier M = 2 02h: Clock Multiplier M = 3 .... : ...................... FFh : Clock Multiplier M = 256
15:14	RTM	R	0h	Re-Tuning Modes This field selects re-tuning method and limits the maximum data length. Bit47-46 Re-Tuning Mode Re-Tuning Method Data Length There are two re-tuning timings: Re-Tuning Request controlled by the Host Controller and expiration of a Re-Tuning Timer controlled by the Host Driver. By receiving either timing, the Host Driver executes the re-tuning procedure just before a next command issue. The maximum data length per read/write command is restricted so that re-tuning procedures can be inserted during data transfers. [1] Re-Tuning Mode 1 The host controller does not have any internal logic to detect when the re-tuning needs to be performed. In this case, the Host Driver should maintain all re-tuning timings by using a Re-Tuning Timer. To enable inserting the re-tuning procedure during data transfers, the data length per read/write command shall be limited up to 4MB. [2] Re-Tuning Mode 2 The host controller has the capability to indicate the re-tuning timing by Re-Tuning Request during data transfers. Then the data length per read/write command shall be limited up to 4MB. During non data transfer, re-tuning timing is determined by either Re-Tuning Request or Re-Tuning Timer. If Re-Tuning Request is used, Re-Tuning Timer should be disabled. [3] Re-Tuning Mode 3 The host controller has the capability to take care of the re-tuning during data transfer [Auto Re-Tuning]. Re-Tuning Request shall not be generated during data transfers and there is no limitation to data length per read/write command. During non data transfer, re-tuning timing is determined by either Re-Tuning Request or Re-Tuning Timer. If Re-Tuning Request is used, Re-Tuning Timer should be disabled. Re-Tuning Timer Control Example for Re-Tuning Mode 1 The initial value of re-tuning timer is provided by Timer Count for Re-Tuning field in this register. The timer starts counting by loading the initial value. When the timer expires, the Host Driver marks an expiration flag. On receiving a command request, the Host driver checks the expiration flag. If the expiration flag is set, then the Host Driver should perform the re-tuning procedure before issuing a command. If the expiration flag is not set, then the Host Driver issues a command without performing the re-tuning procedure. Every time the re-tuning procedure is performed, the timer loads the new initial value and the expiration flag is cleared. Re-Tuning Timer Control Example for Re-Tuning Mode 2 and Mode 3 The timer control is almost the same as Re-Tuning Mode 1 except the timer loads the new initial value after data transfer [when receiving Transfer Complete]. In case of Mode 3, Timer Count for Re-Tuning is set either smaller value: Tuning effective time after re-tuning procedure or after data transfer. If a Host System goes into power down mode, the Host Driver should stop the re-tuning timer and set the expiration flag to 1 when the Host System resumes from power down mode. 3 Reserved 2 Auto Re-Tuning (for transfer) - Timer and Re-Tuning Request 1 Timer and Re-Tuning Request - Max data length 4MB 0 Timer - Max data length 4MB
13	TSDR50	R	0h	Use Tuning for SDR50 If this bit is set to 1, this Host Controller requires tuning to operate SDR50. [Tuning is always required to operate SDR104.] 1 SDR50 requires tuning. 0 SDR50 does not require tuning.
12	RESERVED2	R	0h
11:8	TCRT	R	0h	Timer Count for Re-Tuning This field indicates an initial value of the Re-Tuning Timer for Re-Tuning Mode 1 to 3. Setting to 0 disables Re-Tuning Timer. 15 Get information from other source 14 Reserved 13 Reserved 12 Reserved 11 1024 seconds 10 512 seconds 9 256 seconds 8 128 seconds 7 64 seconds 6 32 seconds 5 16 seconds 4 8 seconds 3 4 seconds 2 2 seconds 1 1 second 0 Re-Tuning Timer disabled
7	RESERVED1	R	0h
6	DTD	R	0h	Driver Type D Support This bit indicates support of Driver Type D for 1.8 Signaling. 1 Driver Type D is Supported 0 Driver Type D is Not Supported.
5	DTC	R	0h	Driver Type C Support This bit indicates support of Driver Type C for 1.8 Signaling. 1 Driver Type C is Supported. 0 Driver Type C is Not Supported.
4	DTA	R	0h	Driver Type A Support This bit indicates support of Driver Type A for 1.8 Signaling. 1 Driver Type A is Supported. 0 Driver Type A is Not Supported.
3	RESERVED	R	0h
2	DDR50	R	0h	DDR50 Support 1 DDR50 is Supported. 0 DDR50 is Not Supported.
1	SDR104	R	0h	SDR104 Support SDR104 requires tuning. 1 SDR104 is Supported. 0 SDR104 is Not Supported.
0	SDR50	R	0h	SDR50 Support If SDR104 is supported, this bit shall be set to 1. Bit 13 indicates whether SDR50 requires tuning or not. 1 SDR50 is Supported. 0 SDR50 is Not Supported.