XC2238M Datasheet, PDF (75/102 Pages) Infineon Technologies AG – 16/32-Bit Single-Chip Microcontroller with 32-Bit Performance XC2000 Family Derivatives / Base Line

XC2238M, XC2239M
XC2000 Family Derivatives / Base Line
Electrical Parameters
Sample time and conversion time of the XC223xM’s A/D converters are programmable.
The timing above can be calculated using Table 19.
The limit values for f_ADCI must not be exceeded when selecting the prescaler value.
Table 19 A/D Converter Computation Table
GLOBCTR.5-0
(DIVA)
000000_B
A/D Converter
Analog Clock f_ADCI
f_SYS
INPCRx.7-0
(STC)
00_H
Sample Time¹⁾
t_S
t_ADCI × 2
000001_B
f_SYS / 2
01_H
000010_B
f_SYS / 3
02_H
:
f_SYS / (DIVA+1)
:
t_ADCI × 3
t_ADCI × 4
t_ADCI × (STC+2)
111110_B
f_SYS / 63
FE_H
t_ADCI × 256
111111_B
f_SYS / 64
FF_H
t_ADCI × 257
1) The selected sample time is doubled if broken wire detection is active (due to the presampling phase).
Converter Timing Example A:
Assumptions: f_SYS
Analog clock
f_ADCI
Sample time
t_S
Conversion 10-bit:
t_C10
Conversion 8-bit:
t_C8
= 80 MHz (i.e. t_SYS = 12.5 ns), DIVA = 03_H, STC = 00_H
= f_SYS / 4 = 20 MHz, i.e. t_ADCI = 50 ns
= t_ADCI × 2 = 100 ns
= 13 × t_ADCI + 2 × t_SYS = 13 × 50 ns + 2 × 12.5 ns = 0.675 μs
= 11 × t_ADCI + 2 × t_SYS = 11 × 50 ns + 2 × 12.5 ns = 0.575 μs
Converter Timing Example B:
Assumptions: f_SYS
Analog clock
f_ADCI
Sample time
t_S
Conversion 10-bit:
t_C10
Conversion 8-bit:
t_C8
= 40 MHz (i.e. t_SYS = 25 ns), DIVA = 02_H, STC = 03_H
= f_SYS / 3 = 13.3 MHz, i.e. t_ADCI = 75 ns
= t_ADCI × 5 = 375 ns
= 16 × t_ADCI + 2 × t_SYS = 16 × 75 ns + 2 × 25 ns = 1.25 μs
= 14 × t_ADCI + 2 × t_SYS = 14 × 75 ns + 2 × 25 ns = 1.10 μs
Data Sheet
75
V2.0, 2009-03