Electronic Components Datasheet Search |
|
DS80C310-ECL Datasheet(PDF) 9 Page - Dallas Semiconductor |
|
DS80C310-ECL Datasheet(HTML) 9 Page - Dallas Semiconductor |
9 / 23 page DS80C310 9 of 23 DUAL DATA POINTER Data memory block moves can be accelerated using the DS80C310 Dual Data Pointer (DPTR). The standard 8032 DPTR is a 16-bit value that is used to address off-chip data RAM or peripherals. In the DS80C310, the standard data pointer is called DPTR and is located at SFR addresses 82h and 83h. These are the standard locations. No modification of standard code is needed to use DPTR. The new DPTR is located at SFR 84h and 85h and is called DPTR1. The DPTR Select bit (DPS) chooses the active pointer and is located at the lsb of the SFR location 86h. No other bits in register 86h have any effect and are set to 0. The user switches between data pointers by toggling the lsb of register 86h. The increment (INC) instruction is the fastest way to accomplish this. All DPTR-related instructions use the currently selected DPTR for any activity. Therefore only one instruction is required to switch from a source to a destination address. Using the Dual Data Pointer saves code from needing to save source and destination addresses when doing a block move. Once loaded, the software simply switches between DPTR0 and 1. The relevant register locations are as follows. DPL 82h Low byte original DPTR DPH 83h High byte original DPTR DPL1 84h Low byte new DPTR DPH1 85h High byte new DPTR DPS 86h DPTR Select (lsb) STOP MODE ENHANCEMENTS Setting bit 1 of the Power Control register (PCON; 87h) invokes the Stop mode. Stop mode is the lowest power state since it turns off all internal clocking. The ICC of a standard Stop mode is approximately 1 µA (but is specified in the Electrical Specifications). The CPU will exit Stop mode from an external interrupt or a reset condition. Internally generated interrupts are not useful since they require clocking activity. The DS80C310 allows a resume from Stop using an INT2-5, which are edge-triggered interrupts. The start-up timing is managed by an internal crystal counter. A delay of 65,536 clocks occurs to give the crystal enough time to start and stabilize. PERIPHERAL OVERVIEW The DS80C310 provides the same peripheral functions as the standard 80C32. It is compatible with the DS80C320 but does not offer all of the peripherals. TIMER RATE CONTROL There is one important difference between the DS80C310 and 8051 regarding timers. The original 8051 used 12 clocks per cycle for timers as well as for machine cycles. The DS80C310 architecture normally uses 4 clocks per machine cycle. However, in the area of timers and serial ports, the DS80C310 will default to 12 clocks per cycle on reset. This allows existing code with real-time dependencies such as baud rates to operate properly. If an application needs higher speed timers or serial baud rates, the user can select individual timers to run at the 4-clock rate. The Clock Control register (CKCON; 8Eh) determines these timer speeds. When the relevant CKCON bit is a logic 1, the DS80C310 uses 4 clocks per cycle to generate timer speeds. When the bit is a 0, the DS80C310 uses 12 clocks for timer speeds. The reset condition is a 0. CKCON.5 selects the speed of Timer 2. CKCON.4 selects Timer 1 and CKCON.3 selects Timer 0. Note that unless a user desires very fast timing, it is unnecessary to alter these bits. Note that the timer controls are independent. |
Similar Part No. - DS80C310-ECL |
|
Similar Description - DS80C310-ECL |
|
|
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 |