2.4 IIR Filter DSP Unit
81
2.4.3 Detailed Register Description
(1) MCSR (Sum-of-products control status register)
[Bit 15] This bit is not used. Read values are undefined. Any values written are invalid.
[Bit 14]
WEY (Write enable bit for Y0 register)
This bit specifies that after calculation, data is transferred to the Y0 register in the bank in which cal-
culation is executed.
When this bit is '1' the 16-bit calculation results in the MDORL register are transferred to the Y0
register. When the value is '0,' no data is transferred.
The initial value of this bit is undefined. It must always be set prior to calculation.
This bit cannot be written to while the DSP unit is executing calculations (when the BF bit=1).
[Bit 13] ] WENY (Write enable bit for next Y0 register)
This bit specifies that after calculation, data is transferred to the next Y0 register following the bank
in which calculation is executed.
When this bit is '1,' the 16-bit calculation results in the MDORL register are transferred to the Y0
register. When the value is '0,' no data is transferred. (For example, when BNK1,0=01, data is writ-
ten to the Y0 register in the C bank.)
The initial value of this bit is undefined. It must always be set prior to calculation.
This bit cannot be written to while the DSP unit is executing calculations (when the BF bit=1).
When BNK1,0=11, calculation results are not transferred to the Y0 register in the A bank.
[Bit 12] WENX (Write enable bit for next X0 register)
This bit specifies that after calculation, data is transferred to the next X0 register following the bank
in which calculation is executed.
When this bit is '1' the 16-bit calculation results in the register are transferred to the X0 register.
When the value is '0,' no data is transferred. (For example, when BNK1,0=01, data is written to the
X0 register in the D bank.)
The initial value of this bit is undefined. It must always be set prior to calculation.
This bit cannot be written to while the DSP unit is executing calculations (when the BF bit=1).
When BNK1,0=11, the result of calculations is not transferred to the X0 in the bank A.
[Bits 11 to 10] Register for setting the number of N1, N0 terms (number of terms for B*Y).
[Bits 9 to 8] Register for setting the number of M1, M0 terms (number of terms for A*X).
These bit determine the number of product terms for sum-of-products. See Table 2.4.3b, where (the
value for N1,0/M1,0) + 1 represents the number of product terms.
Address 00 0081 H
Initial value
–
WEY
WENY WENX
N 1
N 0
M 1
M 0
-XXX XXXX B
15
14
13
12
10
9
11
8
R/W
Address 00 0080 H
Initial value
RND
CLP
DIV
BF
BNK1
BNK0
TRG
MAE
XXX0 XXX0 B
765
4
2
1
30
R/W
R
R/W
W
R/W
The MCRS register bits 15 to 05, 03 and 02 can not be changed while the DSP unit is executing calculations
(when the BF bit=1).