s908ey16g2vfar Freescale Semiconductor, Inc, s908ey16g2vfar Datasheet - Page 255

• Manufacturer Part Number: s908ey16g2vfar
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Verify Routine Options
Carry (C) Bit and Checksum
The first and last addresses of the range to be read and/or compared are specified as parameters in
registers H:X and LADDR, respectively. In the compare option, the carry (C) bit of the condition code
register (CCR) is set if the data in the specified range is verified successfully against the data in the DATA
array. However when the send-out option is selected, the status of the C bit is meaningless because this
function does not include the compare operation. Both options calculate a checksum on data read in the
range. This checksum, which is the LSB of the sum of all bytes in the entire data collection, is stored in A
upon return from the function.
Interrupts are not masked. The COP is serviced in Verify. The first COP is serviced at 24 bus cycles after
this routine is called in the user software. However, the COP timeout might still occur in the send-out
option if the COP is configured for a short timeout period.
Entry Condition
H:X — Contains the beginning address in a range.
LADDR — Contains the last address in a range.
A — When A contains $00, read data is sent out via PTA0 (send-out option is selected). When A contains
a non-zero value, read data is verified against the DATA array (compare option is selected).
DATA array — Contains data to be verified against FLASH data. For the send-out option, the DATA array
is not used.
PTA0 — When the send-out option is selected, this pin must be configured as an input and pulled up in
hardware and PTA0 must be initialized to 0.
Exit Condition
A — Contains a checksum value.
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Send-Out Option — If the accumulator (A) is initialized with $00 at the routine entry, the read data
will be sent out serially through PTA0. The communication baud rate is the same as the baud rate
described in the PutByte routine. When this option is selected, the PTA0 must be pulled up and
configured as an input and the PTA0 data bit must be initialized to 0.
Compare Option — If A is initialized with a non-zero value, the read data is compared against the
DATA array for each byte of FLASH and the DATA array is replaced by the data read from FLASH.
If the data does not match the corresponding value, the data read from FLASH can be confirmed
in the DATA array. All data in the DATA array must be in the zero page, but a range can be beyond
a row size or a page size.
Send-out option
Compare option
Option
MC68HC908EY16A • MC68HC908EY8A Data Sheet, Rev. 1
Used to read a range of FLASH locations and to send the read data to a
host through PTA0 by using the PutByte routine.
Used to read a range of FLASH locations and to compare the read data
against the DATA array
Table 19-11. Verify Routine Options
Description
Routines Supported in ROM
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