HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 559

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

14.4.3
The A/D converter has a built-in sample-and-hold circuit. The A/D converter samples the analog
input at a time t
conversion timing. Table 14.4 indicates the A/D conversion time.
As indicated in figure 14.5, the A/D conversion time includes t
length of t
time therefore varies within the ranges indicated in table 14.4.
In scan mode, the values given in table 14.4 apply to the first conversion time. In the second and
subsequent conversions the conversion time is fixed at 256 states when CKS = 0 or 128 states
when CKS = 1.
Input Sampling and A/D Conversion Time
D
Address bus
Write signal
Input sampling
timing
ADF
Legend:
(1)
(2)
t
t
t
D
SPL
CONV
varies depending on the timing of the write access to ADCSR. The total conversion
D
after the ADST bit is set to 1, then starts conversion. Figure 14.5 shows the A/D
: ADCSR write cycle
: ADCSR address
: A/D conversion start delay
: Input sampling time
: A/D conversion time
(1)
(2)
Figure 14.5 A/D Conversion Timing
t
D
t
SPL
t
CONV
Rev.3.00 Mar. 26, 2007 Page 517 of 772
D
and the input sampling time. The
Section 14 A/D Converter
REJ09B0355-0300