HD6417751RF240V Renesas Electronics America, HD6417751RF240V Datasheet - Page 209

• Manufacturer Part Number: HD6417751RF240V
• Description: MPU 1.5/3.3V 0K PB-FREE 256-QFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH7750r

Specifications of HD6417751RF240V

• Core Processor: SH-4
• Core Size: 32-Bit
• Speed: 240MHz
• Connectivity: EBI/EMI, FIFO, SCI, SmartCard
• Peripherals: DMA, POR, WDT
• Number Of I /o: 39
• Program Memory Type: ROMless
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 1.4 V ~ 1.6 V
• Oscillator Type: External
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 256-QFP Exposed Pad, 256-eQFP, 256-HQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -

3b. Cache miss (no write-back)
3c. Cache miss (with write-back)
4.3.3
When the OC is enabled (CCR.OCE = 1) and data is written by means of an effective address to a
cacheable area, the cache operates as follows:
1. The tag, V bit, and U bit are read from the cache line indexed by effective address bits [13:5].
2. The tag is compared with bits [28:10] of the address resulting from effective address
3a. Cache hit (copy-back)
Data is read into the cache line from the external memory space corresponding to the effective
address. Data reading is performed, using the wraparound method, in order from the longword
data corresponding to the effective address, and when the corresponding data arrives in the
cache, the read data is returned to the CPU. While the remaining one cache line of data is being
read, the CPU can execute the next processing. When reading of one line of data is completed,
the tag corresponding to the effective address is recorded in the cache, and 1 is written to the V
bit.
The tag and data field of the cache line indexed by effective address bits [13:5] are saved in the
write-back buffer. Then data is read into the cache line from the external memory space
corresponding to the effective address. Data reading is performed, using the wraparound
method, in order from the longword data corresponding to the effective address, and when the
corresponding data arrives in the cache, the read data is returned to the CPU. While the
remaining one cache line of data is being read, the CPU can execute the next processing. When
reading of one line of data is completed, the tag corresponding to the effective address is
recorded in the cache, 1 is written to the V bit, and 0 to the U bit. The data in the write-back
buffer is then written back to external memory.
translation by the MMU:
A data write in accordance with the access size (quadword/longword/word/byte) is performed
for the data indexed by bits [4:0] of the effective address and the data field of the cache line
indexed by effective address bits [13:5]. Then 1 is set in the U bit.
• If the tag matches and the V bit is 1
• If the tag matches and the V bit is 0
• If the tag does not match and the V bit is 0
• If the tag does not match, the V bit is 1, and the U bit is 0 → (3c)
• If the tag does not match, the V bit is 1, and the U bit is 1 → (3e)
Write Operation
Rev.4.00 Oct. 10, 2008 Page 109 of 1122
Copy-back
→ (3a)
→ (3c)
→ (3c)
REJ09B0370-0400
Write-through
→ (3b)
→ (3d)
→ (3d)
→ (3d)
→ (3d)
4. Caches