Electronic Components Datasheet Search |
|
5962-8869002LA Datasheet(PDF) 3 Page - Intersil Corporation |
|
5962-8869002LA Datasheet(HTML) 3 Page - Intersil Corporation |
3 / 8 page 6-3 Programming Introduction The HM-6642 is a 512 word by 8-bit field Programmable Read Only Memory utilizing nicrome fusible links as pro- grammable memory elements. Selected memory locations are permanently changed from their manufactured state, of all low (VOL) to a logical high (VOH), by the controlled application of programming potentials and pulses. Careful adherence to the following programming specifications will result in high programming yield. Both high VCC (6.0V) and low VCC (4.0V) verify cycles are specified to assure the integrity of the programmed fuse. This programming specification, although complete, does not preclude rapid programming. The worst case programming time required is 37.4 seconds, and typical programming time can be approximately 4 seconds per device. The chip (E) and output enable (G) are used during the programming procedure. On PROMs which have more than one output enable control G3 is to be used. The other output enables must be held in the active, or enabled, state throughout the entire programming sequence. The program- mer designer is advised that all pins of the programmer’s socket should be at ground potential when the PROM is inserted into the socket. VCC must be applied to the PROM before any input or output pin is allowed to rise (See Note). Overall Programming Procedure 1. The address of the first bit to be programmed is presented, and latched by the chip enable (E) falling edge. The output is disabled by taking the output enable G Low: The programming pin is enabled by taking (P) high. 2. VCC is raised to the programming voltage level, 12.5V. 3. All data output pins are pulled up to VCC program. Then the data output pin corresponding to the bit to be programmed is pulled low for 100ms. Only one bit should be programmed at a time. 4. The data output pin is returned to VCC, and the VCC pin is returned to 6.0V. 5. The address of the bit is again presented, and latched by a second chip enable falling edge. 6. The data outputs are enabled, and read, to verify that the bit was successfully programmed. a). If verified, the next bit to be programmed is addressed and programmed. b). If not verified, the programs verify sequence is repeated up to 8 times total. 7. After all bits to be programmed have been verified at 6.0V, the VCC is lowered to 4.0V and all bits are verified. a). If all bits verify, the device is properly programmed. b). If any bit fails to verify, the device is rejected. Programming System Requirements 1. The power supply for the device to be programmed must be able to be set to three voltages: 4.0V, 6.0V, 12.5V. This supply must be able to supply 500mA average, and 1A dynamic, currents to the PROM during programming. The power supply rise fall times when switching between volt- ages must be no quicker than 1ms. 2. The address drivers must be able to supply a VIH of 4.0V and 6.0V and VIL when the system is at programming voltages. (See Note) 3. The control input buffers must be able to maintain input voltage levels of ≥ 70% and ≤ 20% VCC for VIH and VIL levels, respectively. Notice that chip enable (E) and G does not require a pull up to programming voltage levels. The program control (P) must switch from ground to VIH and from VIH to the VCC PGM level. (See Note) 4. The data input buffers must be able to sink up to 3mA from the PROM’s output pins without rising more than 0.7V above ground, be able to hold the other outputs high with a current source capability of 0.5mA to 2.0mA, and not interfere with the reading and verifying of the data output of the PROM. Notice that a bit to be programmed is changed from a low state (VOL) to high (VOH) by pulling low on the output pin. A suggested implementation is open collector TTL buffers (or inverters) with 4.7k Ω pull up resistors to VCC. (See Note) NOTE: Never allow any input or output pin to rise more than 0.3V above VCC, or fall more than 0.3V below ground. HM-6642 |
Similar Part No. - 5962-8869002LA |
|
Similar Description - 5962-8869002LA |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |