119
•
Bits 15–8 (Reserved): These bits are always read as 0.
•
Bit 7 (Compare Match Flag (CMF)): Indicates whether the values of RTCNT and the refresh
time constant register (RTCOR) match. When 0, the value of RTCNT and RTCOR do not
match; when 1, the value of RTCNT and RTCOR match.
Bit 7: CMF
Description
0
RTCNT value does not equal RTCOR value
(Initial value)
To clear CMF, the CPU must read CMF after it has been set to 1, then write a 0
in this bit
1
RTCNT value is equal to RTCOR value
•
Bit 6 (Compare Match Interrupt Enable (CMIE)): Enables or disables the compare match
interrupt (CMI) generated when CMF is set to 1 in RTCSR (RTCNT value = RTCOR value).
When cleared to 0, the CMI interrupt is disabled; when set to 1, it is enabled.
Bit 6: CMIE
Description
0
Compare match interrupt request (CMI) is disabled
(Initial value)
1
Compare match interrupt request (CMI) is enabled
•
Bits 5–3 (Clock Select Bits 2–0 (CKS2–CKS0)): These bits select the clock input to RTCNT
from among the seven types of clocks created by dividing the system clock (
φ
). When the input
clock is selected with the CKS2–CKS0 bits, RTCNT starts to increment.
Bit 5: CKS2
Bit 4: CKS1
Bit 3: CKS0
Description
0
0
0
Clock input disabled
(Initial value)
1
φ
/2
1
0
φ
/8
1
φ
/32
1
0
0
φ
/128
1
φ
/512
1
0
φ
/2048
1
φ
/4096
•
Bits 2–0 (Reserved): These bits are always read as 0. The write value should always be 0.
Summary of Contents for HD6417032
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Page 525: ...490 CK RAS CAS TRp TRc TRcc tRASD1 tRASD2 tCASD3 tCASD2 TRr tCSR Figure 20 18 Self Refresh ...
Page 578: ...543 CK RAS CAS TRp TRc TRcc tRASD1 tRASD2 tCASD3 tCASD2 TRr tCSR Figure 20 62 Self Refresh ...
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