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2007-10-15
TMP91FW60
14.4.8 RAM Transfer Command
See Table 14-8.
1. From the controller to the device
The data in the 1st byte is used to determine the baud rate. The 1st byte is transferred with receive
operation disabled (SC1MOD0<RXE> = 0). (The baud rate is determined using an internal timer.)
To communicate in UART mode
Send the value 86H from the controller to the target board using UART settings at the desired
baud rate. If the serial operation mode is determined as UART, the device checks to see
whether or not the desired baud rate can be set. If the device determines that the desired baud
rate cannot be set, operation is terminated and no communications can be established.
2. From the device to the controller
The data in the 2nd byte is the ACK response returned by the device for the serial operation mode
setting data sent in the 1st byte. If the data in the 1st byte is found to signify UART and the desired
baud rate can be set, the device returns 86H.
Baud rate determination
The device determines whether or not the desired baud rate can be set. If it is found that the
baud rate can be set, the boot program rewrites the BR1CR and BR1ADD values and returns
86H. If it is found that the desired baud rate cannot be set, operation is terminated and no data
is returned. The controller sets a time-out time (5 seconds) after it has finished sending the
1st byte. If the controller does not receive the response (86H) normally within the time-out
time, it should be considered that the device is unable to communicate. Receive operation is
enabled (SC1MOD0<RXE> = 1) before 86H is written to the transmission buffer.
3. From the controller to the device
The data in the 3rd byte is operation command data. In this case, the RAM Transfer command data
(10H) is sent from the controller to the device.
4. From the device to the controller
The data in the 4th byte is the ACK response to the operation command data in the 3rd byte. First,
the device checks to see if the received data in the 3rd byte contains any error. If a receive error is
found, the device returns the ACK response data for communications error (bit 3) x8H and waits for
the next operation command data (3rd byte). The upper four bits of the ACK response data are unde-
fined (They are the upper four bits of the immediately preceding operation command data).
Next, if the data received in the 3rd byte corresponds to one of the operation commands given in
Table 14-7, the device echoes back the received data (ACK response for normal reception). In the
case of the RAM Transfer command, if read or write protection is not applied, 10H is echoed back
and then execution branches to the RAM transfer processing routine. If protection is applied, the
device returns the corresponding ACK response data (bit 2/1) x6H and waits for the next operation
command data (3rd byte). The upper four bits of the ACK response data are undefined. (They are the
upper four bits of the immediately preceding operation command data.)
After branching to the RAM transfer processing routine, the device checks the data in the password
If the data in the 3rd byte does not correspond to any operation command, the device returns the
ACK response data for operation command error (bit0) x1H and waits for the next operation com-
mand data (3rd byte). The upper four bits of the ACK response data are undefined. (They are the
upper four bits of the immediately preceding operation command data.)