Section 7 Bus State Controller (BSC)
Rev. 2.00 Mar 09, 2006 page 296 of 906
REJ09B0292-0200
Setting
External Address Pins
SZ AMX2 AMX1 AMX0
Output
Timing
A1–A8
A9
A10
A11
A12
A13
A14
A15
0
1
0
0
Column
address
A1–A8
A9
A10
LH
*
1
A12
A21
*
3
A22
*
2
A15
Row
address
A9–A16 A17
A18
A19
A20
A21
*
3
A22
*
2
A23
0
0
1
1
Column
address
A1–A8
L/H
*
1
A18
*
2
A11
A12
A13
A14
A15
Row
address
A9–A16 A17
A18
*
2
A19
A20
A21
A22
A23
0
1
1
1
Column
address
A1–A8
L/H
*
1
A17
*
2
A11
A12
A13
A14
A15
Row
address
A9–A16 A16
A17
*
2
A19
A20
A21
A22
A23
Notes: AMX2–AMX0 setting 110 is reserved and must not be used. When SZ = 0, AMX2–AMX0
settings 001, 010, and 101 are also reserved and must not be used.
1. L/H is a bit used to specify commands. It is fixed at L or H according to the access
mode.
2. Bank address specification.
3. Bank address specification when using four banks.
7.5.3
Burst Reads
Figure 7.22 (a) and (b) show the timing charts for burst reads. In the following example, 2
synchronous DRAMs of 256k
×
16 bits are connected, the data width is 32 bits and the burst
length is 4. After a Tr cycle that performs ACTV command output, a READA command is issued
in the Tc cycle, read data is accepted in cycles Td1 to Td4, and the end of the read sequence is
waited for in the Tde cycle. One Tde cycle is issued when I
φ
: E
φ
≠
1 : 1, and two cycles when I
φ
: E
φ
= 1 : 1. Tap is a cycle for waiting for the completion of the auto-precharge based on the
READA command within the synchronous DRAM. During this period, no new access commands
are issued to the same bank. Accesses of the other bank of the synchronous DRAM by another CS
space are possible. Depending on the TRP1, TRP0 specification in MCR, the chip determines the
number of Tap cycles and does not issue a command to the same bank during that period.
Figure 7.22 (a) and (b) show examples of the basic cycle. Because a slower synchronous DRAM is
connected, setting WCR1 and MCR bits can extend the cycle. The number of cycles from the
ACTV command output cycle Tr to the READA command output cycle Tc can be specified by
bits RCD1 and RCD0 in MCR. 00 specifies 1 cycle, 01 specifies 2 cycles, and 10 specifies 3
cycles. For 2 or 3 cycles, a NOP command issue cycle Trw for the synchronous DRAM is inserted
between the Tr cycle and the Tc cycle. The number of cycles between the READA command
Содержание SH7616
Страница 10: ...Rev 2 00 Mar 09 2006 page x of xxvi ...
Страница 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Страница 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Страница 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Страница 662: ...Section 14 Serial Communication Interface with FIFO SCIF Rev 2 00 Mar 09 2006 page 636 of 906 REJ09B0292 0200 ...
Страница 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Страница 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Страница 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Страница 935: ...SH7616 Hardware Manual ...