526
Bits 1 and 0—Clock Enable 1 and 0 (CKE1, CKE0): Select the SCIF clock source and enable
or disable clock output from the SCK pin. Depending on the combination of CKE1 and CKE0, the
SCK pin can be used for serial clock output or serial clock input.
The CKE0 setting is valid only when the SCIF is operating on the internal clock (CKE1
=
0). The
CKE0 setting is ignored when an external clock source is selected (CKE1
=
1). Before selecting
the SCIF operating mode in the serial mode register (SCSMR), set CKE1 and CKE0. For further
details on selection of the SCIF clock source, see table 16.7 in section 16.3, Operation.
Bit 1: CKE1
Bit 0: CKE0
Description
0
0
Internal clock, SCK pin used for input pin (input signal is
ignored) (Initial
value)
1
Internal clock, SCK pin used for clock output
*
1
1
0
External clock, SCK pin used for clock input
*
2
1
External clock, SCK pin used for clock input
*
2
Notes:
*
1 The output clock frequency is 16 times the bit rate.
*
2 The input clock frequency is 16 times the bit rate.
16.2.7
Serial Status Register (SCSSR)
The serial status register (SCSSR) is a 16-bit register. The upper 8 bits indicate the number of
receive errors in the SCFRDR data, and the lower 8 bits indicate the SCIF operating state.
The CPU can always read and write to SCSSR, but cannot write 1 to the status flags (ER, TEND,
TDFE, BRK, OPER, and DR). These flags can be cleared to 0 only if they have first been read
(after being set to 1). Bits 3 (FER) and 2 (PER) are read-only bits that cannot be written. SCSSR is
initialized to H'0060 by a reset and in standby or module standby mode.
Lower 8 bits:
7
6
5
4
3
2
1
0
ER
TEND
TDFE
BRK
FER
PER
RDF
DR
Initial value:
0
1
1
0
0
0
0
0
R/W:
R/(W)
*
R/(W)
*
R/(W)
*
R/(W)
*
R
R
R/(W)
*
R/(W)
*
Note:
*
The only value that can be written is 0 to clear the flag.
Содержание SH7709S
Страница 2: ...Hitachi SuperH RISC engine SH7709S Hardware Manual ADE 602 250 Rev 1 0 09 21 01 Hitachi Ltd ...
Страница 75: ...56 ...
Страница 107: ...88 ...
Страница 125: ...106 ...
Страница 139: ...120 ...
Страница 203: ...184 ...
Страница 245: ...226 ...
Страница 292: ...273 T1 CKIO A25 to A0 CSn RD WR RD D31 to D0 WEn D31 to D0 BS T2 Read Write Figure 10 6 Basic Timing of Basic Interface ...
Страница 323: ...304 Tp TRr TRrw TRrw CKIO CKE CSn RAS3U RAS3L CASU CASL RD WR Figure 10 28 Synchronous DRAM Auto Refresh Timing ...
Страница 411: ...392 ...
Страница 609: ...590 ...
Страница 635: ...616 ...
Страница 663: ...644 ...
Страница 679: ...660 ...