200 Hitachi
In standby mode or the like when synchronous DRAM and pseudo SRAM are in self-refresh
mode, memory is not precharged until the mode is cleared, so the master cannot release the bus.
Design it so the master puts the slave to sleep before self-refresh mode starts or otherwise prevent
the slave access cycle from starting, which prevents the slave from producing a bus release
request. The slave accesses these types of memories after the master finishes any processing
necessary when the self-refresh mode is cleared, such as refresh settings.
7.11
Other Topics
7.11.1
Resets
The bus state controller only does a complete initialization for a power-on reset. All signals are
immediately negated, regardless of where in the bus cycle the SH7095 is, and the output buffer is
turned off if the bus arbitration mode is slave. Signal negation is simultaneously with turning the
output buffer off. All control registers are initialized. In standby, sleep and manual reset, no bus
state controller control registers are initialized. When a manual reset is performed, any executing
bus cycles are completed, and then the SH7095 waits for an access. When a cache fill or 16-byte
DMAC transfer is executing, the CPU or DMAC that is the bus master ends the access in a
longword unit, since the access request is canceled by the manual reset. This means that when a
manual reset comes in during a cache fill, the cache contents can no longer be guaranteed. During
a manual reset, the RTCNT does not count up, so no refresh request is generated. The refresh
cycle does not start up. To preserve the data of the DRAM, synchronous DRAM or pseudo
SRAM, the pulse width of the manual reset must be shorter than the refresh interval. Master mode
chips accept arbitration requests even when a manual reset signal is asserted. When a reset has
come in only to the chip in master mode while the bus is released, the BGR signal is negated to
indicate this. If the BRLS signal is continuously asserted, the bus release state is maintained.
7.11.2
Access as Seen from the CPU or DMAC
The SH7095 is internally divided into three buses: cache, internal, and peripheral. The CPU and
cache memory are connected to the cache bus, the DMAC and bus state controller are connected
to the internal bus, and the low-speed peripherals and mode registers are connected to the
peripheral bus. The user break controller is connected to both the cache bus and the internal bus.
The internal bus can be accessed from the cache bus, but not the other way around. The peripheral
bus can be accessed from the internal bus, but not the other way around. This results in the
following.
Summary of Contents for SH7095
Page 1: ...SH7095 Hardware User Manual ...
Page 23: ...12 Hitachi ...
Page 63: ...52 Hitachi ...
Page 77: ...66 Hitachi ...
Page 105: ...94 Hitachi Figure 5 14 Pipeline Operation when Interrupts are Enabled by Changing the SR ...
Page 127: ...116 Hitachi ...
Page 152: ...Hitachi 141 Figure 7 8 Example of 32 Bit Data Width SRAM Connection ...
Page 157: ...146 Hitachi Figure 7 13 Synchronous DRAM 32 bit Device Connection ...
Page 161: ...150 Hitachi Figure 7 15 Basic Burst Read Timing Auto Precharge ...
Page 167: ...156 Hitachi Figure 7 20 Burst Read Timing Bank Active Same Row Address ...
Page 168: ...Hitachi 157 Figure 7 21 Burst Read Timing Bank Active Different Row Addresses ...
Page 169: ...158 Hitachi Figure 7 22 Write Timing No Precharge ...
Page 170: ...Hitachi 159 Figure 7 23 Write Timing Bank Active Same Row Address ...
Page 180: ...Hitachi 169 Figure 7 29 Example of a DRAM Connection 32 Bit Data Width ...
Page 190: ...Hitachi 179 Figure 7 36 Example of Pseudo SRAM Connection 1 M pseudo SRAM ...
Page 191: ...180 Hitachi Figure 7 37 Example of Pseudo SRAM Connection 4 M pseudo SRAM ...
Page 209: ...198 Hitachi Figure 7 50 Master and Partial Share Master Connections ...
Page 231: ...220 Hitachi ...
Page 287: ...276 Hitachi ...
Page 307: ...296 Hitachi Note For a CPU writing H AA55 to FRC Figure 11 2 FRC Access Operation Write ...
Page 308: ...Hitachi 297 Note For an FRC reading from a CPU H AA55 Figure 11 3 FRC Access Operation Read ...
Page 333: ...322 Hitachi ...
Page 370: ...Hitachi 359 Figure 13 12 Sample Flowchart for Receiving Multiprocessor Serial Data ...
Page 371: ...360 Hitachi Figure 13 12 Sample Flowchart for Receiving Multiprocessor Serial Data cont ...
Page 395: ...384 Hitachi ...
Page 402: ...Hitachi 391 Figure 15 6 PLL Synchronization Settling Timing ...
Page 408: ...Hitachi 397 Figure 15 13 Bus Release Timing Slave Mode With PLL1 Off ...
Page 436: ...Hitachi 425 Figure 15 33 Synchronous DRAM Mode Register Write Cycle TRP 1 Cycle ...
Page 437: ...426 Hitachi Figure 15 34 Synchronous DRAM Mode Register Write Cycle TRP 2 Cycles ...
Page 449: ...438 Hitachi Figure 15 46 DRAM CAS Before RAS Refresh Cycle TRP 1 Cycle TRAS 2 Cycles PLL On ...
Page 454: ...Hitachi 443 Figure 15 51 DRAM CAS Before RAS Refresh Cycle TRP 1 Cycle TRAS 2 Cycles PLL Off ...
Page 461: ...450 Hitachi Figure 15 58 Pseudo SRAM Auto Refresh Cycle PLL On TRP 1 Cycle TRAS 2 Cycles ...
Page 462: ...Hitachi 451 Figure 15 59 Pseudo SRAM Self Refresh Cycle PLL On TRP 1 Cycle TRAS 2 Cycles ...
Page 467: ...456 Hitachi Figure 15 64 Pseudo SRAM Auto Refresh Cycle PLL Off TRP 1 Cycle TRAS 2 Cycles ...
Page 468: ...Hitachi 457 Figure 15 65 Pseudo SRAM Self Refresh Cycle PLL Off TRP 1 Cycle TRAS 2 Cycles ...
Page 471: ...460 Hitachi Figure 15 68 Interrupt Vector Fetch Cycle PLL On No Waits ...
Page 472: ...Hitachi 461 Figure 15 69 Interrupt Vector Fetch Cycle PLL Off No Waits ...
Page 473: ...462 Hitachi Figure 15 70 Interrupt Vector Fetch Cycle 1 External Wait Cycle ...
Page 474: ...Hitachi 463 Figure 15 71 Address Monitor Cycle ...
Page 490: ...Hitachi 479 B 2 Register Chart ...