Motorola DragonBall MC9328MX1 Reference Manual page 398

Multimedia Accelerator (MMA)
Table 17-3. MMA MAC Control Register Description (Continued)
Name
X INDEX LOAD X Index Load—Determines whether the index in the
Bit 28 XDAC module is loaded with the values in the
MMA_MAC_XINDEX register for every
(MMA_MAC_XCOUNT + 1) iteration. When set, the Index
is reloaded with the MMA_MAC_XINDEX register value.
When cleared, the index retains the last stored value.
X_DATA_SEL X Data Select—Selects which bits in the 32-bit data bus
Bit 27 are used to create the 24-bit operand.
Note: When the cache is enabled, X_DATA_SEL must
be set to one.
X SIGN ALT X Operand Sign Alternate—Determines whether the X
Bit 26 operand alternates its operand sign of the operation.
X SIGN INI X Operand Initial Sign—Determines the X operand initial
Bit 25 sign of the operation with x.
X SIGNED X Operand Signed—Determines whether the X operand
Bit 24 is signed or unsigned. When set, the X operand is a signed
value. When cleared, the X operand is unsigned.
Y MODIFY Y Modify Preset—Presets MMA_MAC_YMODIFY register
PRESET to value 0x00000004.
Bit 23
Y INDEX CLR Y Index Clear—Setting this bits clears the
Bit 22 MMA_MAC_YINDEX register to value 0x00000000.
Y INDEX INCR Y Index Increment—Determines whether the
Bit 21 MMA_MAC_YINDEX register in the YDAC module is
incremented by the value in the MMA_MAC_YINCR
register for every (MMA_MAC_YCOUNT + 1) iteration.
Y INDEX INCR is used with Y INDEX LOAD.
Y INDEX LOAD Y Index Load—Determines whether the index in the
Bit 20 YDAC module is loaded with the values in the
MMA_MAC_YINDEX register for every
(MMA_MAC_YCOUNT + 1) iteration. When set, the index
is reloaded with the MMA_MAC_YINDEX register value.
When cleared, the index retains the last stored value.
Y_DATA_SEL Y Data Select—Selects which bits in the 32-bit data bus
Bit 19 are used to create the 24-bit operand.
Y SIGN ALT Y Operand Sign Alternate—Determines whether the Y
Bit 18 operand alternates its operand sign of the operation.
Y SIGN INI Y Operand Initial Sign—Determines whether the Y
Bit 17 operand initial sign of the operation with y.
17-8
Description
MC9328MX1 Reference Manual
Settings
0 = XDAC index register is not
reloaded
1 = XDAC index register is
reloaded
0 = Bits [23:0] used as operand
1 = Bits [31:8] used as operand
0 = X operand sign is not
alternated
1 = X operand sign is alternated
0 = +(x)
1 = -(x)
0 = X operand is unsigned
1 = X operand is signed
0 = MMA_MAC_YMODIFY
Register is not preset
1 = MMA_MAC_YMODIFY
Register is preset to value
0x00000004
0 = MMA_MAC_YINDEX is not
reset
1 = MMA_MAC_YINDEX is reset
to value of 0x000 0000
0 = MMA_MAC_YINDEX is not
incremented
1 = MMA_MAC_YINDEX is
incremented
0 = Index register is not reloaded
1 = Index register is reloaded
0 = Bits [23:0] used as operand
1 = Bits [31:8] used as operand
0 = Y operand sign is not
alternated
1 = Y operand sign is alternated
0 = +(y)
1 = -(y)
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