Enhanced Multiply-Accumulate Unit (EMAC)
MCF52235 ColdFire® Integrated Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
4-7
4.2.3
Accumulator Registers (ACC0–3)
The accumulator registers store 32-bits of the MAC operation result. The accumulator extension registers
form the entire 48-bit result.
Figure 4-4. Accumulator Registers (ACC0–3)
4.2.4
Accumulator Extension Registers (ACCext01, ACCext23)
Each pair of 8-bit accumulator extension fields are concatenated with the corresponding 32-bit
accumulator register to form the 48-bit accumulator. For more information, see
Figure 4-5. Accumulator Extension Register (ACCext01)
BDM: 0x806 (ACC0)
0x809 (ACC1)
0x80A (ACC2)
0x80B (ACC3)
Access: User read/write
BDM read/write
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
R
Accumulator
W
Reset – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
Table 4-5. ACC0–3 Field Descriptions
Field
Description
31–0
Accumulator
Store 32-bits of the result of the MAC operation.
BDM: 0x807 (ACCext01)
Access: User read/write
BDM read/write
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
R
ACC0U
ACC0L
ACC1U
ACC1L
W
Reset – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
Table 4-6. ACCext01 Field Descriptions
Field
Description
31–24
ACC0U
Accumulator 0 upper extension byte
23–16
ACC0L
Accumulator 0 lower extension byte
15–8
ACC1U
Accumulator 1 upper extension byte
7–0
ACC1L
Accumulator 1 lower extension byte
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
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currently
are
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available
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for
import
or
sale
in
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United
States
prior
to
September
2010:MCF52234CVM60,
MCF52235CVM60
