| ??? 10/23/09 06:11 Read: times |
#169988 - switch 12 to 6clock mode using IAP for P89V51RD2 Responding to: ???'s previous message |
The clock doubling option can be enabled using an external programmer or by IAP calls.
For X2 mode the EDC bit in FST register has to be set. The IAP calls are made using a common interface PGM_MTP at 1FF0H. IAP function Double Clock R1= 05H DPL=05H If the operation is successfull ACC=00H else ACC<>0 indicates failure. Flash memory: block 0 is 64K for P89V51RD2 and block 1 is 8K containing IAP/ISP routines. Access to the IAP routines in block 1 are enabled by [Bank Select Bit] BSEL=0 in sfr FCF (FCF.0) Also the [Software Reset Bit] SWR bit =0 (FCF.1) in order to access the IAP routines in block 1. However it is obvious that a different physical memory is mapped to the first 8K (0000H-1FFFH) so the user code has to be very carefull how to use it. A critical point is that the X2 mode is only for the internal system clock and the internal flash memory. The XTAL2 output is not doubled. For detailed information you have to study carefull the relative datasheet of P89V51RD2 http://www.nxp.com/acrobat/datasheets/P89V51RB2_RC2_RD2_4.pdf K.L.Angelis |
| Topic | Author | Date |
| 89v51rd2(NXP)switching clock 12 to 6 through software | 01/01/70 00:00 | |
| Not possible in software for P89C51RD2 | 01/01/70 00:00 | |
| not switchable | 01/01/70 00:00 | |
| switch 12 to 6clock mode using IAP for P89V51RD2 | 01/01/70 00:00 | |
| one-way function | 01/01/70 00:00 | |
| 12 to 6clock is a One Time action for P89V51RD2 | 01/01/70 00:00 | |
| You may well be right | 01/01/70 00:00 | |
12 to 6 clock, and documentation | 01/01/70 00:00 |