R5F61668RN50FPV Renesas Electronics America, R5F61668RN50FPV Datasheet - Page 352

• Manufacturer Part Number: R5F61668RN50FPV
• Description: IC H8SX/1668 MCU FLASH 144LQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8SX/1600r

Specifications of R5F61668RN50FPV

• Core Processor: H8SX
• Core Size: 16/32-Bit
• Speed: 50MHz
• Connectivity: EBI/EMI, I²C, IrDA, SCI, SmartCard, USB
• Peripherals: DMA, LVD, POR, PWM, WDT
• Number Of I /o: 92
• Program Memory Size: 1MB (1M x 8)
• Program Memory Type: FLASH
• Ram Size: 56K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: External
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 144-LQFP
• For Use With: R0K561668S000BE - KIT STARTER FOR H8SX/1668R0K561664S001BE - KIT STARTER FOR H8SX/1651HS0005KCU11H - EMULATOR E10A-USB H8S(X),SH2(A)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Section 9 Bus Controller (BSC)
9.11.10 Controlling Write-Precharge Delay
In an SDRAM write cycle, a certain time is required until the write operation is completed inside
of the SDRAM. When the time between the WRIT command and the subsequent PALL command
does not meet a given specification, the Trwl cycle can be inserted for one cycle by the TRWL bit
in SDCR. Whether or not to insert the Trwl cycle depends on the SDRAM to be used and the
frequency of this LSI.
Figure 9.68 shows a timing example when one Trwl cycle is inserted.
Rev. 2.00 Sep. 24, 2008 Page 318 of 1468
REJ09B0412-0200
Figure 9.68 Write Timing Example when Write-Precharge Delay Cycle Insertion
Precharge-sel
Address bus
D15 to D8
SDRAMφ
D7 to D0
DQMLU
DQMLL
RD/WR
RAS
CAS
CKE
WE
CS
BS
PALL
T
Row address
p
(TRWL = 1)
High
address
ACTV
Row
T
r
NOP
T
c1
Column address
WRIT
T
c2
NOP
T
rwl