SH7727 Datasheet, PDF (746/1109 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family/SH7700 Series

Section 21 Analog Front End Interface (AFEIF)
(2) HC Control Sequence
AFEIF module supports hardware control STLC7550 that is an AFE manufactured by ST
microelectronics. Figure 21.6 shows the AFE control sequence.
Write 1 to HC bit of ACTR1
AFE_FS
AFE_TXOUT
Data word
(1)
Sampling period
1/2 sampling period
(3)
Mode change
(5)
Data word
(2)
Control word
(4)
Data word
AFE_HC1
HC0: Kept to 1
Write "1" to HC bit of ACTR1
AFE I/F
STLC7550
DATA
FS for data
DATA
HC1 goes to 1
DATA
DATA
HC1 goes to 0
DATA
DATA
FS for data
FS for data
FS for control word
FS for data
AFE mode change
FS for data
1. If the CPU write "1" to the HC bit of ACTR1, the AEFIF drives AFE_HC1 to "H" right after
transmit next data.
2. AFE fetches the HC1's status of "H" at rising edgge of next AFE_FS.
3. AFE output the FS at the next 1/2 sampling period and then AFEIF transfer the AFE
control word.
4. AFEIF keeps AFE_HC1 to "H" for 2nd FS and return to "L" after transmit the control word.
5. AFE fetches the AFE_HC1's status of "L" and changes the mode of itself.
Figure 21.6 AFE Control Sequence
Rev. 5.00 Dec 12, 2005 page 674 of 1034
REJ09B0254-0500