PRODUCT SPECIFICATION
TMC2330A
Timing Diagrams
No Accumulation
tPWH
2
tS
tPWL
tH
0
1
3
…
22
23
CLK
…
…
…
…
…
RTP, TCXY
ACC[1:0]
00
00
EN
B
00
EN
C
ENXR,
ENYP[1:0]
EN
A
XRIN[15:0],
YPIN[31:0]
tD
tHO
RXOUT[15:0],
PYOUT[15:0]
f(A)
f(B)
Note: OERX = OEPY = LOW
Phase Modulation
0
1
2
3
…
22
23
24
25
CLK
RTP, TCXY
ACC[1:0]
…
00
01
01
01
01
…
…
…
…
ENXR
R
10
C
XRIN[15:0]
ENYP[1:0]
YPIN[31:0]
01
I
01
J
01
K
01
L
RXOUT[15:0]
PYOUT[15:0]
C + I
2C + J
3C + K
4C + L
Notes:
1. OERX = OEPY = LOW
2. Carrier C and amplitude R loaded on CLK0.
3. Modulation Values I, J, K, L… Loaded on CLK1, CLK2, etc.
4. Output corresponding to modulation loaded at CLKi emerged tDO after CLKi + 21.
5. To modulate amplitude, vary XRIN with ENXR = 1.
Applications Discussion
In signed magnitude mode, overflows are circularly symmet-
rical—if a given radius overflows at an angle P, it will also
overflow at the angles π-P, π+P, and -P. This is because -X
will overflow if and only if X overflows, and -Y will over-
flow if and only if Y overflows.
Numeric Overflow
Because the TMC2330A accommodates 16-bit unsigned
radii and 16-bit signed Cartesian coordinates, Polar-To-
Rectangular conversions can overflow for incoming radii
greater than 32767= 7FFFh and will overflow for all incom-
ing radii greater than 46341=B505h. (ln signed magnitude
mode, a radius of 46340 = B504h will also overflow at all
angles.) The regions of overflow and of correct conversion
are illustrated in Figure 1.
In two’s complement mode, the number system’s asymmetry
complicates the overflow conditions slightly. An input vector
with an X component of -32768=8000h will not overflow,
whereas one with an X component of +32768 will. Table 3
summarizes several simple cases of overflow and near-over-
flow.
10
REV. 1.1.8 10/31/00
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
