ez80190 ZiLOG Semiconductor, ez80190 Datasheet - Page 135

• Manufacturer Part Number: ez80190
• Description: Ez80190 Microprocessor
• Manufacturer: ZiLOG Semiconductor

PS006613-0306
Recommended Operation
nificant bit is 0. If the 40-bit MACC Accumulator value is read using a succession
of 8-bit reads, the procedure appears as follows:
1. Read the least significant byte from the MACC Accumulator
2. Read the second byte from the MACC Accumulator
3. Read the third byte from the MACC Accumulator
4. Read the fourth byte from the MACC Accumulator
5. Read the most significant byte from the MACC Accumulator
In Example 2, notice that the upper 3 bits of the final read contain copies of the
sign bit (in this example, the sign bit is 0, which represents a positive number).
Setting Up A New Calculation
The following procedure sets up a new calculation.
1. Load the data into the MACC’s x and y RAM spaces.
2. Read the status register, MACC_STAT. If the DATA bank status is EMPTY or
3. Use the OTI2R instruction to load the new calculation. Registers to be written
4. If the MACC is ready to begin a new calculation (CALC bank is EMPTY or
DATA_OUT[7:0] = MACC_AC0[7:0] = MACC Accumulator [10:3]
DATA_OUT[7:0] = MACC_AC1[7:0] = MACC Accumulator [18:11]
DATA_OUT[7:0] = MACC_AC2[7:0] = MACC Accumulator [26:19]
DATA_OUT[7:0] = MACC_AC3[7:0] = MACC Accumulator [34:27]
DATA_OUT[7:0] = MACC_AC4[7:0] = {000b, MACC Accumulator [39:35]}
DONE, a new calculation can be written to the DATA bank registers. If the
DATA bank status is DONE, the result currently available in the MACC
Accumulator registers are lost if not read prior to a write.
may include nearly any combination of MACC_xSTART, MACC_xEND,
MACC_xRELOAD, MACC_ySTART, MACC_yEND, MACC_yRELOAD,
MACC_LENGTH, MACC_CTL, and MACC_ACx. If the OTI2R instruction is
set up to end with either MACC_CTL or any of the MACC_ACx registers, the
DATA bank status changes to READY.
DONE), the banks are automatically switched to begin execution. The
equation that is set up in the DATA bank is transferred to the CALC bank. The
CALC bank status changes to IN PROGRESS.
PRELIMINARY
eZ80190 Product Specification
Multiply-Accumulator
121