k2xx (k212, k222, k224) Modem chips 19880829/Hubert Hoefsloot | Send | Receive | Dev. | | K212 | K222 | K224 | Mod. | baud | freq | baud | freq | +- | ----------------------------------------------------------------------------- Bell 103 | yes | yes | yes | FSK | 300 | 1170 | 300 | 2125 | 100 | Bell 212A | yes | yes | yes | DPSK | 1200 | 1200 | 1200 | 2400 | | V.21 | no | yes | yes | FSK | 300 | 1080 | 300 | 1750 | 100 | V.22 | no | yes | yes | DPSK | 600 | 1200 | 600 | 2400 | | V.22 | yes | yes | yes | DPSK | 1200 | 1200 | 1200 | 2400 | | V.22 bis | no | no | yes | QAM | 2400 | 1200 | 2400 | 2400 | | K212/K222/K224| CR0 | CR1 | CR2 | CR3 | CR4 | CR5 | CR6 | baud | ---------------------------------------------------------------- Bell 103 Org.| &32 | &30 | rrr | &00 | --- | --- | ID | 300 | Bell 103 Ans.| &33 | &30 | rrr | &20 | --- | --- | ID | 300 | Bell 212A Org.| &1a | &20 | rrr | &00 | --- | --- | ID | 1200 | Bell 212A Ans.| &1b | &20 | rrr | &20 | --- | --- | ID | 1200 | K222/K224 ---------------------------------------------------------------- Bell 212A Org.| &9a | &20 | rrr | &00 | --- | --- | ID | 600 | Bell 212A Ans.| &9b | &20 | rrr | &20 | --- | --- | ID | 600 | V.21 Org.| &b2 | &30 | rrr | &00 | --- | --- | ID | 300 | V.21 Ans.| &b3 | &30 | rrr | &21 | --- | --- | ID | 300 | V.22 Org.| &b2 | &30 | rrr | &00 | --- | --- | ID | 600 | V.22 Ans.| &b3 | &30 | rrr | &21 | --- | --- | ID | 600 | FSK --> Frequency Shift Keying DPSK --> Double Phase-Shift Keying QAM --> Quad Amplitude Modulation The data that in DPSK over the PTT line is transmitted or received is eventually synchronous. The data that via the TxD pin enters must be 1200 baud sync or async. If the data is async, it is (via the ASYNC/SYNC rate converter) converted to sync. ,pg CONTROL REGISTER CR0 adres 00 ------------------------- Modul. Option | ---------------------- \ Modul. Type | | ------------------- / | | | ---------------- \ | | | | ------------- | Transmit Mode | | | | | ---------- / | | | | | | ------- Transmit Enable | | | | | | | ---- Answer/Originate | | | | | | | | 7 6 5 4 3 2 1 0 ----------------------------------------------------------------- 0 Select answer mode 1 Select originate mode 0 Disables transmit output at TXA 1 Enables transmit output at TXA 0 0 0 Select power down 0 0 1 Internal sync. 0 1 0 External sync. 0 1 1 Slave sync. 1 0 0 Async. 1 start, 6 data, 1 stop 1 0 1 Async. 1 start, 7 data, 1 stop 1 1 0 Async. 1 start, 8 data, 1 stop 1 1 1 Async. 1 start, 8 data, parity and/or 1 or 2 stop 0 0 0 DPSK | V.22 | 1200 baud 0 0 1 FSK | Bell 103 | 300 baud 0 1 0 QAM | V.22 bis | 2400 baud 1 0 0 DPSK | V.22 alt.B | 600 baud 1 0 1 FSK | V.21 | 300 baud ,pg CONTROL REGISTER CR1 adres 01 ------------------------- \ Transmit Pattern | ---------------------- / | | ------------------- Enable Detect Interrupt | | | ---------------- Bypass Scrambler | | | | ------------- Clock Control | | | | | ---------- Reset | | | | | | ------- \ Test Mode | | | | | | | ---- / | | | | | | | | 7 6 5 4 3 2 1 0 ----------------------------------------------------------------- 0 0 Select mormal operating mode 0 1 Select remote digital loopback 1 0 Analog loopback mode 1 1 Select local digital loopback 0 Select normal operation 1 Reset modem to power down state 0 Select 11.0592 MHz 1 Select 19.2 KHz 0 Select normal operation for DPSK modulatie 1 Select scrambler bypass for DPSK modulatie 0 Disables interrup at /INT pin 1 Enables /INT output 0 0 Select normal data transmission at TXD pin 0 1 Select alternating mark/space output for testing 1 0 Select constant mark transmit pattern 1 1 Select constant space transmit pattern ,pg CONTROL REGISTER DR adres 02 ------------------------- Not used | ---------------------- Not used | | ------------------- Receive Data | | | ---------------- Unscrambled Mark | | | | ------------- Carrier Detect | | | | | ---------- Answer Tone Received | | | | | | ------- Call Progress Detect | | | | | | | ---- Long Loop | | | | | | | | 7 6 5 4 3 2 1 0 ----------------------------------------------------------------- 0 Indicates normal received signal 1 Indicates low received signal level (< -38 dBm) 0 No call progress tone detected 1 Indicates presense of call progress tones 0 No answer tone detected 1 Indicates detection of 2225 Hz answer tone 0 No carrier detected in the receive channel 1 Carrier detected in the receive channel 0 No unscrambled mark 1 Indicared detection of unscrambled marks X Continuously output the received data stream