Electronic Components Datasheet Search |
|
CY14B101LA-SP45XIT Datasheet(PDF) 7 Page - Cypress Semiconductor |
|
CY14B101LA-SP45XIT Datasheet(HTML) 7 Page - Cypress Semiconductor |
7 / 28 page CY14B101LA CY14B101NA Document #: 001-42879 Rev. *L Page 7 of 28 SRAM write operations that are in progress when HSB is driven LOW by any means are given time (tDELAY) to complete before the STORE operation is initiated. However, any SRAM write cycles requested after HSB goes LOW are inhibited until HSB returns HIGH. In case the write latch is not set, HSB is not driven LOW by the CY14B101LA/CY14B101NA. But any SRAM read and write cycles are inhibited until HSB is returned HIGH by MPU or other external source. During any STORE operation, regardless of how it is initiated, the CY14B101LA/CY14B101NA continues to drive the HSB pin LOW, releasing it only when the STORE is complete. Upon completion of the STORE operation, the nvSRAM memory access is inhibited for tLZHSB time after HSB pin returns HIGH. Leave the HSB unconnected if it is not used. Hardware RECALL (Power-up) During power-up or after any low power condition (VCC<VSWITCH), an internal RECALL request is latched. When VCC again exceeds the VSWITCH on power up, a RECALL cycle is automatically initiated and takes tHRECALL to complete. During this time, the HSB pin is driven LOW by the HSB driver and all reads and writes to nvSRAM are inhibited. Software STORE Data is transferred from the SRAM to the nonvolatile memory by a software address sequence. The CY14B101LA/CY14B101NA Software STORE cycle is initiated by executing sequential CE or OE controlled read cycles from six specific address locations in exact order. During the STORE cycle an erase of the previous nonvolatile data is first performed, followed by a program of the nonvolatile elements. After a STORE cycle is initiated, further input and output are disabled until the cycle is completed. Because a sequence of READs from specific addresses is used for STORE initiation, it is important that no other read or write accesses intervene in the sequence, or the sequence is aborted and no STORE or RECALL takes place. To initiate the Software STORE cycle, the following read sequence 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 0x8FC0 Initiate STORE cycle The software sequence may be clocked with CE controlled reads or OE controlled reads, with WE kept HIGH for all the six READ sequences. After the sixth address in the sequence is entered, the STORE cycle commences and the chip is disabled. HSB is driven LOW. After the tSTORE cycle time is fulfilled, the SRAM is activated again for the read and write operation. Software RECALL Data is transferred from the nonvolatile memory to the SRAM by a software address sequence. A Software RECALL cycle is initiated with a sequence of read operations in a manner similar to the Software STORE initiation. To initiate the RECALL cycle, 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 0x4C63 Initiate RECALL cycle Internally, RECALL is a two step procedure. First, the SRAM data is cleared. Next, the nonvolatile information is transferred into the SRAM cells. After the tRECALL cycle time, the SRAM is again ready for read and write operations. The RECALL operation does not alter the data in the nonvolatile elements. Table 1. Mode Selection CE WE OE BHE, BLE[15] A15–A0[16] Mode I/O Power H X X X X Not selected Output high Z Standby L H L L X Read SRAM Output data Active L L X L X Write SRAM Input data Active L H L X 0x4E38 0xB1C7 0x83E0 0x7C1F 0x703F 0x8B45 Read SRAM Read SRAM Read SRAM Read SRAM Read SRAM AutoStore Disable Output data Output data Output data Output data Output data Output data Active[17] Notes 15. BHE and BLE are applicable for x16 configuration only. 16. While there are 17 address lines on the CY14B101LA (16 address lines on the CY14B101NA), only the 13 address lines (A14 - A2) are used to control software modes. Rest of the address lines are do not care. 17. The six consecutive address locations must be in the order listed. WE must be HIGH during all six cycles to enable a nonvolatile cycle. [+] Feedback |
Similar Part No. - CY14B101LA-SP45XIT |
|
Similar Description - CY14B101LA-SP45XIT |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |