
Enhanced Multiply-Accumulate Unit (EMAC)
4-6
Freescale Semiconductor
The and operator enables the MASK use and causes bit 5 of the extension word to be set. The exact
algorithm for the use of MASK is:
if extension word, bit [5] = 1, the MASK bit, then
if <ea> = (An)
oa = An and {0xFFFF, MASK}
if <ea> = (An)+
oa = An
An = (An + 4) and {0xFFFF, MASK}
if <ea> =-(An)
oa = (An - 4) and {0xFFFF, MASK}
An = (An - 4) and {0xFFFF, MASK}
if <ea> = (d16,An)
oa = (An + se_d16) and {0xFFFF0x, MASK}
Here,
oa
is the calculated operand address and
se_d16
is a sign-extended 16-bit displacement. For
auto-addressing modes of post-increment and pre-decrement, the updated An value calculation is also
shown.
Use of the post-increment addressing mode, {(An)+} with the MASK is suggested for circular queue
implementations.
Figure 4-3. Mask Register (MASK)
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.
BDM: 0x805 (MASK)
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 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
MASK
W
Reset 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
Table 4-4. MASK Field Descriptions
Field
Description
31–16
Reserved, must be set.
15–0
MASK
Performs a simple AND with the operand address for MAC instructions.
MCF5329 Reference Manual, Rev 3
Summary of Contents for MCF5329
Page 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...