Renesas Hitachi H8S/2191, Руководство по оборудованию, Страница: 684 / 1065

Rev. 2.0, 11/00, page 657 of 1037
(2) HSW Mode Register 2 (HSM2)
0
0
1
0
R
2
0
R/W
3
0
4
0
R/W
0
R/W
5 6
0
7
EDG ISEL1 SOFG OFG VFF/NFF
0
R/W
FRT
W R/W R
FGR20FF LOP
Bit :
Initial value :
R/W :
HSM2 is a register which confirms and determines the operational state of the HSW timing
generator.
HSM2 is an 8-bit register. Bits 6 and 1 are read-only bits, and write is disabled. Bit 0 is a write-
only bit, and if a read is attempted, an undetermined value is read out. All the other bits accept
both read and write. It is initialized to H'00 by a reset or stand-by.
Bit 7: Free-run Bit (FRT)
Selects whether timing is matched to the DPG counter and timer, or to free-running counter.
Bit 7
FRT Description
0 5-bit DFG c 16-bit timer counter (Initial value)
1 16-bit FRC
Bit 6: FRG2 Clear Stop Bit (FGR2OFF)
Nullifies the clearing of the counter by the DFG reference register 2. The FIFO group, including
both FIFO1 and FIFO2, is available.
Bit 6
FGR2OFF Description
0 Validates the clearing of the 16-bit timer counter by DFG reference register 2
(Initial value)
1 Nullifies the clearing of the 16-bit timer counter by DFG reference register 2
Bit 5: Mode Selection Bit (LOP)
Selects the output mode of FIFO. If the loop mode is selected, LOB3 to LOB0 bits and LOA3 to
LOA0 bits become valid. If the LOP bit is rewritten, the pointer which counts the writing
position of FIFO is cleared. In this case, the ultimate output date is kept.
Bit 5
LOP Description
0 Single mode (Initial value)
1 Loop mode