Raspberry Pi /RP2350 /QMI /M1_RFMT

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Interpret as M1_RFMT

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 0 (S)PREFIX_WIDTH 0 (S)ADDR_WIDTH 0 (S)SUFFIX_WIDTH 0 (S)DUMMY_WIDTH 0 (S)DATA_WIDTH 0 (NONE)PREFIX_LEN 0 (NONE)SUFFIX_LEN 0 (NONE)DUMMY_LEN 0 (DTR)DTR

SUFFIX_LEN=NONE, DUMMY_WIDTH=S, DUMMY_LEN=NONE, DATA_WIDTH=S, SUFFIX_WIDTH=S, PREFIX_WIDTH=S, PREFIX_LEN=NONE, ADDR_WIDTH=S

Description

Read transfer format configuration for memory address window 1.

Configure the bus width of each transfer phase individually, and configure the length or presence of the command prefix, command suffix and dummy/turnaround transfer phases. Only 24-bit addresses are supported.

The reset value of the M1_RFMT register is configured to support a basic 03h serial read transfer with no additional configuration.

Fields

PREFIX_WIDTH

The transfer width used for the command prefix, if any

0 (S): Single width

1 (D): Dual width

2 (Q): Quad width

ADDR_WIDTH

The transfer width used for the address. The address phase always transfers 24 bits in total.

0 (S): Single width

1 (D): Dual width

2 (Q): Quad width

SUFFIX_WIDTH

The width used for the post-address command suffix, if any

0 (S): Single width

1 (D): Dual width

2 (Q): Quad width

DUMMY_WIDTH

The width used for the dummy phase, if any.

If width is single, SD0/MOSI is held asserted low during the dummy phase, and SD1…SD3 are tristated. If width is dual/quad, all IOs are tristated during the dummy phase.

0 (S): Single width

1 (D): Dual width

2 (Q): Quad width

DATA_WIDTH

The width used for the data transfer

0 (S): Single width

1 (D): Dual width

2 (Q): Quad width

PREFIX_LEN

Length of command prefix, in units of 8 bits. (i.e. 2 cycles for quad width, 4 for dual, 8 for single)

0 (NONE): No prefix

1 (8): 8-bit prefix

SUFFIX_LEN

Length of post-address command suffix, in units of 4 bits. (i.e. 1 cycle for quad width, 2 for dual, 4 for single)

Only values of 0 and 8 bits are supported.

0 (NONE): No suffix

2 (8): 8-bit suffix

DUMMY_LEN

Length of dummy phase between command suffix and data phase, in units of 4 bits. (i.e. 1 cycle for quad width, 2 for dual, 4 for single)

0 (NONE): No dummy phase

1 (4): 4 dummy bits

2 (8): 8 dummy bits

3 (12): 12 dummy bits

4 (16): 16 dummy bits

5 (20): 20 dummy bits

6 (24): 24 dummy bits

7 (28): 28 dummy bits

DTR

Enable double transfer rate (DTR) for read commands: address, suffix and read data phases are active on both edges of SCK. SDO data is launched centre-aligned on each SCK edge, and SDI data is captured on the SCK edge that follows its launch.

DTR is implemented by halving the clock rate; SCK has a period of 2 x CLK_DIV throughout the transfer. The prefix and dummy phases are still single transfer rate.

If the suffix is quad-width, it must be 0 or 8 bits in length, to ensure an even number of SCK edges.

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