PRODUCT SPECIFICATION
TMC2330A
Timing Diagrams
No Accumulation
tS
tH
CLK
0
1
2
tPWH
tPWL
3
…
22
23
RTP, TCXY
ACC[1:0]
ENXR,
ENYP[1:0]
XRIN[15:0],
YPIN[31:0]
RXOUT[15:0],
PYOUT[15:0]
00
EN
A
00
EN
B
00
EN
C
…
…
…
…
tD
…
f(A)
tHO
f(B)
Note:
OERX = OEPY = LOW
Phase Modulation
CLK
RTP, TCXY
ACC[1:0]
ENXR
XRIN[15:0]
ENYP[1:0]
YPIN[31:0]
RXOUT[15:0]
PYOUT[15:0]
R
10
C
01
I
01
J
01
K
01
L
00
01
01
01
01
…
…
…
…
…
C+I
2C + J
3C + K
4C + L
0
1
2
3
…
22
23
24
25
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
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 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.
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.
REV. 1.1.8 10/31/00
10
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
