Section 7 Bus State Controller (BSC)
Rev. 2.00 Mar 09, 2006 page 279 of 906
REJ09B0292-0200
When the CMIE bit in RTCSR is set to 1, an interrupt request is sent to the controller by this
match signal. The interrupt request is output continuously until the CMF bit in RTCSR is cleared.
When the CMF bit clears, it only affects the interrupt; the refresh request is not cleared by this
operation. When a refresh is performed and refresh requests are counted using interrupts, a refresh
can be set simultaneously with the interval timer interrupt.
Bits 15 to 8—Reserved: These bits are always read as 0. The write value should always be 0.
7.3
Access Size and Data Alignment
7.3.1
Connection to Ordinary Devices
Byte, word, and longword are supported as access units
.
Data is aligned based on the data width of
the device
.
Therefore, reading longword data from a byte-width device requires four read
operations
.
The bus state controller automatically converts data alignment and data length between
interfaces. An 8-bit, 16-bit, or 32-bit external device data width can be connected by using the
mode pins for the CS0 space, or by setting BCR2 for the CS1–CS4 spaces. However, the data
width of devices connected to the respective spaces is specified statically, and the data width
cannot be changed for each access cycle. Figures 7.5 to 7.7 show the relationship between device
data widths and access units.
D31
7
0
D23
D15
D7
D0
15
8
7
0
7
0
7
0
7
0
A24–A0
000000
000001
000002
000003
000000
000002
000000
Data input/output pin
Byte read/write of address 0
Byte read/write of address 1
Byte read/write of address 2
Byte read/write of address 3
Word read/write of address 0
Word read/write of address 2
Longword read/write of address 0
31
24
23
16
15
8
7
0
15
8
7
0
32-bit external device (ordinary)
Figure 7.5 32-Bit External Devices and Their Access Units
Summary of Contents for SH7616
Page 10: ...Rev 2 00 Mar 09 2006 page x of xxvi ...
Page 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Page 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Page 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Page 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Page 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Page 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Page 935: ...SH7616 Hardware Manual ...