T32UC3L0128_14 Datasheet, PDF (766/852 Pages) ATMEL Corporation – Compact Single-cycle RISC Instruction Set Including DSP Instructions

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31.5.3.4
Table 31-21. MEMORY_SIZED_ACCESS Details (Continued)
Instructions
Details
DR output value (Address phase)
xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
DR output value (Data read phase) xxxxxeb dddddddd dddddddd dddddddd dddddddd
DR output value (Data write phase) xxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxeb
MEMORY_WORD_ACCESS
This instruction allows access to the entire Service Access Bus data area. Data is accessed
through the 34 MSB of the SAB address, a direction bit, and 32 bits of data. This instruction is
identical to MEMORY_SIZED_ACCESS except that it always does word sized accesses. The
size field is implied, and the two lowest address bits are removed and not scanned in.
Note: This instruction was previously known as MEMORY_ACCESS, and is provided for back-
wards compatibility.
The data register is alternately interpreted by the SAB as an address register and a data regis-
ter. The SAB starts in address mode after the MEMORY_WORD_ACCESS instruction is
selected, and toggles between address and data mode each time a data scan completes with
the busy bit cleared.
Starting in Run-Test/Idle, SAB data is accessed in the following way:
1. Select the IR Scan path.
2. In Capture-IR: The IR output value is latched into the shift register.
3. In Shift-IR: The instruction register is shifted by the TCK input.
4. Return to Run-Test/Idle.
5. Select the DR Scan path.
6. In Shift-DR: Scan in the direction bit (1=read, 0=write) and the 34-bit address of the
data to access.
7. Go to Update-DR and re-enter Select-DR Scan.
8. In Shift-DR: For a read operation, scan out the contents of the addressed area. For a
write operation, scan in the new contents of the area.
9. Return to Run-Test/Idle.
For any operation, the full 34 bits of the address must be provided. For write operations, 32 data
bits must be provided, or the result will be undefined. For read operations, shifting may be termi-
nated once the required number of bits have been acquired.
Table 31-22. MEMORY_WORD_ACCESS Details
Instructions
Details
IR input value
10001 (0x11)
IR output value
peb01
DR Size
35 bits
DR input value (Address phase)
aaaaaaaa aaaaaaaa aaaaaaaa aaaaaaaa aar
DR input value (Data read phase)
xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxx
DR input value (Data write phase)
dddddddd dddddddd dddddddd dddddddd xxx
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