AT90S8515

Manufacturer Part NumberAT90S8515
Description8-bit microcontroller with 8K bytes in-system programmable flash, 2.7-6.0V
ManufacturerATMEL Corporation
AT90S8515 datasheet
 
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Page 18/112:

The Parallel Instruction Fetches and Instruction Executions

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AT90S8515
18
Figure 20. The Parallel Instruction Fetches and Instruction Executions
T1
System Clock Ø
1st Instruction Fetch
1st Instruction Execute
2nd Instruction Fetch
2nd Instruction Execute
3rd Instruction Fetch
3rd Instruction Execute
4th Instruction Fetch
Figure 21 shows the internal timing concept for the register file. In a single clock cycle
an ALU operation using two register operands is executed and the result is stored back
to the destination register.
Figure 21. Single Cycle ALU Operation
T1
System Clock Ø
Total Execution Time
Register Operands Fetch
ALU Operation Execute
Result Write Back
The internal data SRAM access is performed in two System Clock cycles as described
in Figure 22.
Figure 22. On-chip Data SRAM Access Cycles
T1
System Clock Ø
Address
Prev. Address
Data
WR
Data
RD
See “Interface to External SRAM” on page 60 for a description of the access to the
external SRAM.
T2
T3
T2
T3
T2
T3
T4
Address
T4
T4
0841G–09/01