Cypress CY14B108M, CY14B108K Preventing AutoStore, Mode Selection, A15 A05 Mode Power, Recall

PRELIMINARY CY14B108K, CY14B108M

Table 2. Mode Selection

CE	WE	OE,	BHE,	BLE	[3]	A15 - A0[5]	Mode	I/O	Power
H	X		X			X	Not Selected	Output High Z	Standby
L	H		L			X	Read SRAM	Output Data	Active
L	L		X			X	Write SRAM	Input Data	Active
L	H		L			0x4E38	Read SRAM	Output Data	Active[6]
						0xB1C7	Read SRAM	Output Data
						0x83E0	Read SRAM	Output Data
						0x7C1F	Read SRAM	Output Data
						0x703F	Read SRAM	Output Data
						0x8B45	AutoStore	Output Data
							Disable
L	H		L			0x4E38	Read SRAM	Output Data	Active[6]
						0xB1C7	Read SRAM	Output Data
						0x83E0	Read SRAM	Output Data
						0x7C1F	Read SRAM	Output Data
						0x703F	Read SRAM	Output Data
						0x4B46	AutoStore	Output Data
							Enable
L	H		L			0x4E38	Read SRAM	Output Data	Active ICC2[6]
						0xB1C7	Read SRAM	Output Data
						0x83E0	Read SRAM	Output Data
						0x7C1F	Read SRAM	Output Data
						0x703F	Read SRAM	Output Data
						0x8FC0	Nonvolatile	Output High Z
							STORE
L	H		L			0x4E38	Read SRAM	Output Data	Active[6]
						0xB1C7	Read SRAM	Output Data
						0x83E0	Read SRAM	Output Data
						0x7C1F	Read SRAM	Output Data
						0x703F	Read SRAM	Output Data
						0x4C63	Nonvolatile	Output High Z
							RECALL

Preventing AutoStore

The AutoStore function is disabled by initiating an AutoStore disable sequence. A sequence of read operations is performed in a manner similar to the Software STORE initiation. To initiate the AutoStore disable sequence, the following sequence of CE or OE controlled read operations must be performed:

1.Read address 0x4E38 Valid READ

2.Read address 0xB1C7 Valid READ

3.Read address 0x83E0 Valid READ

4.Read address 0x7C1F Valid READ

5.Read address 0x703F Valid READ

6.Read address 0x8B45 AutoStore Disable

AutoStore is re-enabled by initiating an AutoStore enable sequence. A sequence of read operations is performed in a

manner similar to the software RECALL initiation. To initiate the AutoStore enable sequence, the following sequence of CE or OE controlled read operations must be performed:

1.Read address 0x4E38 Valid READ

2.Read address 0xB1C7 Valid READ

3.Read address 0x83E0 Valid READ

4.Read address 0x7C1F Valid READ

5.Read address 0x703F Valid READ

6.Read address 0x4B46 AutoStore Enable

If the AutoStore function is disabled or re-enabled, a manual STORE operation (hardware or software) issued to save the AutoStore state through subsequent power down cycles. The part comes from the factory with AutoStore enabled.

Notes

5.While there are 20 address lines on the CY14B108K (19 address lines on the CY14B108M), only the 13 address lines (A14 - A2) are used to control software modes. The remaining address lines are don’t care.

6.The six consecutive address locations must be in the order listed. WE must be HIGH during all six cycles to enable a nonvolatile cycle.

Document #: 001-47378 Rev. ** Page 5 of 29

[+] Feedback