Electronic Components Datasheet Search |
|
24LC256TECS16K Datasheet(PDF) 8 Page - Microchip Technology |
|
24LC256TECS16K Datasheet(HTML) 8 Page - Microchip Technology |
8 / 42 page 24AA256/24LC256/24FC256 DS20001203T-page 8 1998-2013 Microchip Technology Inc. 5.0 DEVICE ADDRESSING A control byte is the first byte received following the Start condition from the master device (Figure 5-1). The control byte consists of a 4-bit control code. For the 24XX256, this is set as ‘ 1010’ binary for read and write operations. The next three bits of the control byte are the Chip Select bits (A2, A1, A0). The Chip Select bits allow the use of up to eight 24XX256 devices on the same bus and are used to select which device is accessed. The Chip Select bits in the control byte must correspond to the logic levels on the corresponding A2, A1 and A0 pins for the device to respond. These bits are, in effect, the three Most Significant bits of the word address. For the MSOP package, the A0 and A1 pins are not connected. During device addressing, the A0 and A1 Chip Select bits (Figures 5-1 and 5-2) should be set to ‘0’. Only two 24XX256 MSOP packages can be connected to the same bus. The last bit of the control byte defines the operation to be performed. When set to a one, a read operation is selected. When set to a zero, a write operation is selected. The next two bytes received define the address of the first data byte (Figure 5-2). Because only A14…A0 are used, the upper address bits are a “don’t care.” The upper address bits are transferred first, followed by the Less Significant bits. Following the Start condition, the 24XX256 monitors the SDA bus checking the device type identifier being transmitted. Upon receiving a ‘ 1010’ code and appropriate device select bits, the slave device outputs an Acknowledge signal on the SDA line. Depending on the state of the R/W bit, the 24XX256 will select a read or write operation. FIGURE 5-1: CONTROL BYTE FORMAT 5.1 Contiguous Addressing Across Multiple Devices The Chip Select bits A2, A1 and A0 can be used to expand the contiguous address space for up to 2 Mbit by adding up to eight 24XX256 devices on the same bus. In this case, software can use A0 of the control byte as address bit A15; A1 as address bit A16; and A2 as address bit A17. It is not possible to sequentially read across device boundaries. For the MSOP package, up to two 24XX256 devices can be added for up to 512 Kbit of address space. In this case, software can use A2 of the control byte as address bit A17. Bits A0 (A15) and A1 (A16) of the control byte must always be set to a logic ‘0’ for the MSOP. FIGURE 5-2: ADDRESS SEQUENCE BIT ASSIGNMENTS 10 1 0 A2 A1 A0 S ACK R/W Control Code Chip Select Bits Slave Address Acknowledge Bit Start Bit Read/Write Bit 1 010 A 2 A 1 A 0 R/W x A 11 A 10 A 9 A 7 A 0 A 8 •• • • •• A 12 Control Byte Address High Byte Address Low Byte Control Code Chip Select Bits x = “don’t care” bit A 13 A 14 |
Similar Part No. - 24LC256TECS16K |
|
Similar Description - 24LC256TECS16K |
|
|
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 |