MC96FR116C
November, 2018 Rev.1.8
183
going, active low. This bit is auto-set when operation is done.
0
Busy (Operation processing)
1
Operation completed
VFYGOOD
Auto-verification result flag
0
Auto-verification failed
1
Auto-verification succeeded
PCRCRD
CRC calculation data read control. For correct operation, clear the
FARH, FARM and FARL before starting CRC or setting READ bit in
FEMR.
0
Reading FARH, FARM and FARL registers return checksum
value (24-bit)
1
Reading FARM and FARL registers return CRC result (16-bit)
ROMINT
FLASH Interrupt Flag. This bit is auto-cleared when program, erase, or
verify operation is started.
0
No interrupt requested
1
Interrupt requested
PMODE
Program mode flag
EMODE
Erase mode flag
VMODE
Verify mode flag
FTCR (FLASH Time control Register)
EE
H
7
6
5
4
3
2
1
0
TCR7
TCR6
TCR5
TCR4
TCR3
TCR2
TCR1
TCR0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value : 00
H
TCR[7:0]
Program or Erase Time control
Program or erase time is controlled by the value in FTCR register.
The FLASH Memory controller includes a 10-bit counter used to calculate program or erase time. The
counter is clocked by a clock which is divided by 64 from system clock(XIN/64). It
’s a simple counter.
When program or erase operation starts, the counter is cleared and start up-counting until it reaches
the target value coming from FTCR. On matching, the counter stops and the PEVBSY flag is set.
In bulk erase mode, the TCR[7:0] becomes the most significant eight bits in counter target value, and
the least significant two bits are filled with
“11”. In program or erase mode, the most significant two bit
is filled with
‘01, the least significant bit is filled with ‘1’, and the TCR[7:0] becomes the middle eight
bits in counter target value. So the program or erase time is calculated by the following equation. In
the following equation and description, it is assumed that the frequency of external clock source, f
XIN
is
8MHz. In that case, the period of XIN/64 clock is about 8us.
Tpe = (TCR+1) * 2 * 8us
Tbe = (TCR+1) * 4 * 8us
where Tpe is time to be taken when program or erase operation is performed in byte- or page-size,
Tbe is time for bulk erase operation.
Normally the maximum program or erase time can be 8us * 512
≒
4ms. And considering the error rate
of ±10%, about 3.6~4.4ms of program/erase time can be ensured. Similarly in bulk erase mode, the
maximum time can be 8ms, so 7.2~8.8ms of bulk erase time will be applied.