AM625: QSPI NAND connection

Koichiro Tashiro

Part Number: AM625

Hi,

My customer is planning to use QSPI-NAND device in their system.
The system is boot-up from this QSPI-NAND. After boot-up, they want to access the QSPI-NAND with 100MHz clock.
There are multiple QSPI/OSPI data capture modes, but it is not clear what is maximum clock for each mode.
- PHY mode with reference clock (No loopback)
- PHY mode with internal PHY loopback
- PHY mode with Internal Pad loopback
- PHY mode with External Board loopback
- PHY mode with DQS (available only for OSPI)
- TAP mode

According to TRM section 5.4.1, it seems LBCLKO loopback is required to support high speed QSPI without DQS signal.

If so, No Loopback, Internal PHY Loopback or Internal Pad Loopback cannot be used for 100MHz normal operation?
Then External Board Loopback (Figure 9-2 in datasheet) must be used?

Thanks and regards,
Koichiro Tashiro

over 1 year ago

0 Kallikuppa Sreenivasa over 1 year ago

TI__Guru**** 190189 points

Hello Koichiro Tashiro

Thank you for the query.

Let me assign to the expert to answer.

Regards,

Sreenivasa

0 Lucas Bowe over 1 year ago in reply to Kallikuppa Sreenivasa

TI__Expert 5505 points

Greetings Koichiro,

Section 7.11.5.18 OSPI in the datasheet (under Timing and Switching Characteristics) for the timing requirements in each mode, in addition the switching characteristics will provide the maximum frequency of operation in each mode.

Sincerely,

Lucas

0 Koichiro Tashiro over 1 year ago in reply to Lucas Bowe

TI__Mastermind 22935 points

Hi Lucas,

I checked datasheet, but it is still not clear enough. I summarized the maximum frequency in each mode. Please fill below table.

OSPI.xlsx

Thanks and regards,
Koichiro Tashiro

0 Lucas Bowe over 1 year ago in reply to Koichiro Tashiro

TI__Expert 5505 points

Greetings Koichiro,

The *excel* datasheet correctly has all the modes that we support for that particular device, the other modes are possible but not supported.

Sincerely,

Lucas

0 Koichiro Tashiro over 1 year ago in reply to Lucas Bowe

TI__Mastermind 22935 points

Hi Lucas,

I understood all "?" in my previous excel are "Not supported".

	PHY				TAP
	SDR		DDR		SDR	DDR
reference clock	w/ data training	w/o data training	w/ data training	w/o data training
No Loopback	NA	NA	NA	NA	50MHz(Table 7-122)	25MHz(Table 7-124)
Internal PHY Loopback	Not supported	166MHz or 142MHz (Table 7-116, 7-117)	Not supported	Not supported	NA	NA
Internal PAD Loopback	Not supported	Not supported	Not supported	Not supported	NA	NA
External Board Loopback	Not supported	166MHz or 142MHz (Table 7-116, 7-117)	Not supported	52MHz (Table 7-119, 7-120)	NA	NA
DQS	Not supported	Not supported	166MHz or 132MHz (Table 7-113, 7-114)	52MHz (Table 7-119, 7-120)	NA	NA

Thanks and regards,
Koichiro Tashiro

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AM625: QSPI NAND connection