DS72011RB120FPV Renesas Electronics America, DS72011RB120FPV Datasheet - Page 220

• Manufacturer Part Number: DS72011RB120FPV
• Description: IC SH7201 MPU ROMLESS 176LQFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH7200r

Specifications of DS72011RB120FPV

• Core Size: 32-Bit
• Core Processor: SH-2A
• Speed: 120MHz
• Connectivity: CAN, EBI/EMI, FIFO, I²C, SCI, Serial Sound
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 104
• Program Memory Type: ROMless
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 70°C
• Package / Case: 176-LQFP
• No. Of I/o's: 109
• Ram Memory Size: 32KB
• Cpu Speed: 120MHz
• Digital Ic Case Style: LQFP
• Supply Voltage Range: 3V To 3.6V
• Operating Temperature Range: -20°C To +70°C
• Embedded Interface Type: I2C, SSI
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: R0K572011S000BE - KIT STARTER FOR SH7201HS0005KCU11H - EMULATOR E10A-USB H8S(X),SH2(A)
• Eeprom Size: -
• Program Memory Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

Section 8 Cache
(2)
In write-back mode, an external bus cycle starts when a write miss occurs, and the entry is
updated. The way to be replaced follows table 8.4. When the U bit of the entry to be replaced is 1,
the cache update cycle starts after the entry is transferred to the write-back buffer. Data is written
to the cache, the U bit is set to 1, and the V bit is set to 1. LRU is updated so that the replaced way
becomes the latest. After the cache completes its update cycle, the write-back buffer writes the
entry back to the memory. The write-back unit is 16 bytes.
In write-through mode, no write to cache occurs in a write miss; the write is only to the external
memory.
8.3.5
When the U bit of the entry to be replaced in the write-back mode is 1, it must be written back to
the external memory. To increase performance, the entry to be replaced is first transferred to the
write-back buffer and fetching of new entries to the cache takes priority over writing back to the
external memory. After the cache completes to fetch the new entry, the write-back buffer writes
the entry back to external memory. During the write-back cycles, the cache can be accessed. The
write-back buffer can hold one line of cache data (16 bytes) and its physical address. Figure 8.3
shows the configuration of the write-back buffer.
Operations in sections 8.3.2 to 8.3.5 are compiled in table 8.8
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Write Miss
A (31 to 4):
Longword 0 to 3: One line of cache data to be written to external memory
A (31 to 4)
Write-Back Buffer (Only for Operand Cache)
Physical address written to external memory (upper three bits are 0)
Figure 8.3 Write-Back Buffer Configuration
Longword 0
Longword 1
Longword 2
R01UH0026EJ0300 Rev. 3.00
Longword 3
SH7201 Group
Sep 24, 2010