ez80190 ZiLOG Semiconductor, ez80190 Datasheet - Page 129

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

PS006613-0306
MACC Dual Bank Operation
DATA Bank Status
MACC_STAT[1:0]
00b
01b
10b
11b
Caution:
Alternatives to OTI2R and INI2R
The INI2R and OTI2R instructions are recommended for CPU input and output
access to the MACC control registers. However, it is not required that only these
instructions be employed. Other I/O instructions can also be used.
The Multiply-Accumulator is divided into two separate operating banks. As a
result, one bank of the MACC performs a set of multiply-accumulate operations on
a set of data while the eZ80190 device is preparing the other bank for the next set
of multiply-accumulate operations. Each bank features a separate accumulator
and a separate set of control register values (MACC_xSTART, MACC_xEND,
MACC_xRELOAD, MACC_ySTART, MACC_yEND, MACC_yRELOAD, and
MACC_LENGTH).
The MACC bank that is currently accessible in the eZ80190 device’s I/O space is
referred to as the DATA bank. The MACC bank that is currently available for use
by the MACC for execution is referred to as the CALC bank. The current state of
the DATA bank is provided by the DATA_STAT field (bits [1:0]) of the
MACC_STAT register. The current state of the CALC bank is provided by the
CALC_STAT field (bits [3:2]) of the MACC_STAT register. An explanation of each
bank status code is indicated in Tables 57 and 58.
Care must be taken to ensure that the High byte of the I/O address,
ADDR[15:8], is only set to
MACC DATA and CALC banks.
Table 57. MACC DATA Bank Status Codes
Description
The DATA bank is EMPTY. No calculation is set up for
execution.
The DATA bank is READY. Calculation is prepared for
execution as soon as the MACC is ready to begin a new
calculation.
Invalid.
The DATA bank is DONE. The DATA bank accumulator
registers contain the result from a recently completed
calculation. This result is not yet read by the CPU.
PRELIMINARY
01h
when a state change is required on the
eZ80190 Product Specification
Multiply-Accumulator
115