37.8.2 Control B


Bit	31	30	29	28	27	26	25	24
	DLYCS[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	23	22	21	20	19	18	17	16
	DLYBCT[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	15	14	13	12	11	10	9	8
					DATALEN[3:0]
Access					R/W	R/W	R/W	R/W
Reset					0	0	0	0


Bit	7	6	5	4	3	2	1	0
			CSMODE[1:0]		SMEMREG	WDRBT	LOOPEN	MODE
Access			R/W	R/W	R/W	R/W	R/W	R/W
Reset			0	0	0	0	0	0

Bits 31:24 – DLYCS[7:0] Minimum Inactive CS Delay

This bit field defines the minimum delay between the inactivation and the activation of CS. The DLYCS time guarantees the Client minimum deselect time.

If DLYCS is 0x00, one CLK_QSPI_AHB period will be inserted by default.

Otherwise, the following equation determines the delay:

DLYCS = Minimum inactive × fperipheral clock

Bits 23:16 – DLYBCT[7:0] Delay Between Consecutive Transfers

This field defines the delay between two consecutive transfers with the same peripheral without removing the chip select. The delay is always inserted after each transfer and before removing the chip select if needed.

When DLYBCT=0x00, no delay between consecutive transfers is inserted and the clock keeps its duty cycle over the character transfers. In Serial Memory mode (MODE=1), DLYBCT is ignored and no delay is inserted. Otherwise, the following equation determines the delay:

DLYBCT = (Delay Between Consecutive Transfers × fperipheral clock) / 32

Bits 11:8 – DATALEN[3:0] Data Length

The DATALEN field determines the number of data bits transferred. Reserved values should not be used.

Value	Name	Description
0x0	8BITS	8-bits transfer
0x1	9BITS	9-bits transfer
0x2	10BITS	10-bits transfer
0x3	11BITS	11-bits transfer
0x4	12BITS	12-bits transfer
0x5	13BITS	13-bits transfer
0x6	14BITS	14-bits transfer
0x7	15BITS	15-bits transfer
0x8	16BITS	16-bits transfer
0x9-0xF		Reserved

Bits 5:4 – CSMODE[1:0] Chip Select Mode

The CSMODE field determines how the chip select is de-asserted.

Value	Name	Description
0x0	NORELOAD	The chip select is de-asserted if TD has not been reloaded before the end of the current transfer.
0x1	LASTXFER	The chip select is de-asserted when the bit LASTXFER is written at 1 and the character written in TD has been transferred.
0x2	SYSTEMATICALLY	The chip select is de-asserted systematically after each transfer.
0x3		Reserved

Bit 3 – SMEMREG Serial Memory Register Mode

Value	Description
0	Serial memory registers are written via AHB access.
1	Serial memory registers are written via APB access. Reset the QSPI.

Bit 2 – WDRBT Wait Data Read Before Transfer

This bit determines the Wait Data Read Before Transfer option.

Bit 1 – LOOPEN Local Loopback Enable

This bit defines if the Local Loopback is enabled or disabled.

LOOPEN controls the local loopback on the data serializer for testing in SPI Mode only. (MISO is internally connected on MOSI).

Value	Description
0	Local Loopback is disabled.
1	Local Loopback is enabled.

Bit 0 – MODE Serial Memory Mode

This bit defines if the QSPI is in SPI Mode or Serial Memory Mode.

Value	Name	Description
0	SPI	SPI operating mode
1	MEMORY	Serial Memory operating mode

Name:	CTRLB
Offset:	0x04
Reset:	0x00000000
Property:	PAC Write-Protection