 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
COP87L88EGN-XE Datasheet(PDF) 7 Page - National Semiconductor (TI) |
|
|
||||||||||||||||||||||||||||||
COP87L88EGN-XE Datasheet(HTML) 7 Page - National Semiconductor (TI) |
|
|
7 / 42 page  Pin Descriptions (Continued) Since G6 is an input only pin and G7 is the dedicated CKO clock output pin (crystal clock option) or general purpose input (RC clock option) the associated bits in the data and configuration registers for G6 and G7 are used for special purpose functions as outlined below Reading the G6 and G7 data bits will return zeros Note that the chip will be placed in the HALT mode by writ- ing a ‘‘1’’ to bit 7 of the Port G Data Register Similarly the chip will be placed in the IDLE mode by writing a ‘‘1’’ to bit 6 of the Port G Data Register Writing a ‘‘1’’ to bit 6 of the Port G Configuration Register enables the MICROWIREPLUS to operate with the alter- nate phase of the SK clock The G7 configuration bit if set high enables the clock start up delay after HALT when the RC clock configuration is used Config Reg Data Reg G7 CLKDLY HALT G6 Alternate SK IDLE Port G has the following alternate features G0 INTR (External Interrupt Input) G2 T1B (Timer T1 Capture Input) G3 T1A (Timer T1 IO) G4 SO (MICROWIRETM Serial Data Output) G5 SK (MICROWIRE Serial Clock) G6 SI (MICROWIRE Serial Data Input) Port G has the following dedicated functions G1 WDOUT WATCHDOG andor Clock Monitor dedicat- ed output G7 CKO Oscillator dedicated output or general purpose input Port C is an 8-bit IO port The 40-pin device does not have a full complement of Port C pins The unavailable pins are not terminated A read operation for these unterminated pins will return unpredicatable values PORT I is an eight-bit Hi-Z input port The 28-pin device does not have a full complement of Port I pins The unavail- able pins are not terminated ie they are floating A read operation for these unterminated pins will return unpredict- able values The user must ensure that the software takes this into account by either masking or restricting the access- es to bit operations The unterminated Port I pins will draw power only when addressed Port I1 – I3 are used for Comparator 1 Port I4 – I6 are used for Comparator 2 The Port I has the following alternate features I1 COMP1bIN (Comparator 1 Negative Input) I2 COMP1aIN (Comparator 1 Positive Input) I3 COMP1OUT (Comparator 1 Output) I4 COMP2bIN (Comparator 2 Negative Input) I5 COMP2aIN (Comparator 2 Positive Input) I6 COMP2OUT (Comparator 2 Output) Port D is an 8-bit output port that is preset high when RESET goes low The user can tie two or more D port out- puts together in order to get a higher drive Functional Description The architecture of the device is modified Harvard architec- ture With the Harvard architecture the control store pro- gram memory (ROM) is separated from the data store mem- ory (RAM) Both ROM and RAM have their own separate addressing space with separate address buses The archi- tecture though based on Harvard architecture permits transfer of data from ROM to RAM CPU REGISTERS The CPU can do an 8-bit addition subtraction logical or shift operation in one instruction (tc) cycle time There are six CPU registers A is the 8-bit Accumulator Register PC is the 15-bit Program Counter Register PU is the upper 7 bits of the program counter (PC) PL is the lower 8 bits of the program counter (PC) B is an 8-bit RAM address pointer which can be optionally post auto incremented or decremented X is an 8-bit alternate RAM address pointer which can be optionally post auto incremented or decremented SP is the 8-bit stack pointer which points to the subroutine interrupt stack (in RAM) The SP is initialized to RAM ad- dress 06F with reset S is the 8-bit Data Segment Address Register used to ex- tend the lower half of the address range (00 to 7F) into 256 data segments of 128 bytes each All the CPU registers are memory mapped with the excep- tion of the Accumulator (A) and the Program Counter (PC) PROGRAM MEMORY The program memory consists of 4096 bytes of ROM These bytes may hold program instructions or constant data (data tables for the LAID instruction jump vectors for the JID instruction and interrupt vectors for the VIS instruction) The program memory is addressed by the 15-bit program counter (PC) All interrupts in the devices vector to program memory location 0FF Hex DATA MEMORY The data memory address space includes the on-chip RAM and data registers the IO registers (Configuration Data and Pin) the control registers the MICROWIREPLUS SIO shift register and the various registers and counters asso- ciated with the timers (with the exception of the IDLE timer) Data memory is addressed directly by the instruction or indi- rectly by the B X SP pointers and S register The device has 192 bytes of RAM Sixteen bytes of RAM are mapped as ‘‘registers’’ at addresses 0F0 to 0FF Hex These registers can be loaded immediately and also decre- mented and tested with the DRSZ (decrement register and skip if zero) instruction The memory pointer registers X SP B and S are memory mapped into this space at address locations 0FC to 0FF Hex respectively with the other regis- ters being available for general usage The instruction set permits any bit in memory to be set reset or tested All IO and registers (except A and PC) are memory mapped therefore IO bits and register bits can be directly and individually set reset and tested The accumu- lator (A) bits can also be directly and individually tested Note RAM contents are undefined upon power-up http www nationalcom 7 |
Similar Part No. - COP87L88EGN-XE |
|
Similar Description - COP87L88EGN-XE |
|
|
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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
