HD6417727F100C Renesas Electronics America, HD6417727F100C Datasheet - Page 166

• Manufacturer Part Number: HD6417727F100C
• Description: IC SUPERH MPU ROMLESS 240QFP
• Manufacturer: Renesas Electronics America
• Series: SuperH® SH7700r

Specifications of HD6417727F100C

• Core Processor: SH-3 DSP
• Core Size: 32-Bit
• Speed: 100MHz
• Connectivity: FIFO, SCI, SIO, SmartCard, USB
• Peripherals: DMA, LCD, POR, WDT
• Number Of I /o: 104
• Program Memory Type: ROMless
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.6 V ~ 2.05 V
• Data Converters: A/D 6x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 240-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -

Section 3 Memory Management Unit (MMU)
3.3.3
A TLB address comparison is performed when an instruction is fetched from a program in
external memory or data in external memory is referenced. The items used in the comparison are
VPN and ASID. The VPN of the logical address that accesses external memory is compared to the
VPN of the TLB entry selected with the index number. The ASID within the PTEH is compared to
the ASID of the indexed TLB entry. All four ways are searched simultaneously. If the compared
values match, and the indexed TLB entry is valid (V bit = 1), the hit is registered.
It is necessary to have software ensure that TLB hits do not occur simultaneously in more than one
way, as hardware operation is not guaranteed if this occurs. For example, if there are two identical
TLB entries with the same VPN and a setting is made such that a TLB hit is made only by a
process with ASID = H'FF when one is in the shared state (SH = 1) and the other in the non-shared
state (SH = 0), then if the ASID in PTEH is set to H'FF, there is a possibility of simultaneous TLB
hits in both these ways. It is therefore necessary to ensure that this kind of setting is not made by
software.
The object compared varies depending on the page management information (SZ, SH) in the TLB
entry. It also varies depending on whether the system supports multiple virtual memory or single
virtual memory.
The page-size information determines whether VPN (11, 10) is compared. VPN (11, 10) is
compared for 1-kbyte pages (SZ = 0) but not for 4-kbyte pages (SZ = 1).
Rev.6.00 Mar. 27, 2009 Page 108 of 1036
REJ09B0254-0600
31
0
Virtual address
31
TLB Address Comparison
VPN(31−17)
Index
VPN(11−10)
17
Address array
16
Figure 3.7 TLB Indexing (IX = 0)
12
11
ASID(7−0)
0
V
Ways 0 to 3
PPN(31−10) PR(1−0) SZ C
Data array
D SH