HC11 A Series
8K ROM (A8), ROMless (A0,A1), 256 RAM, 512 EEPROM (A1,A8), SPI, SCI, 3 IC 5 OC, 8 channel 8 bit A/D.
Nice new device developed together with AT&T. ROMless, on board bank switching to support memory maps of up to 256K. Totally glueless interface - Chip selects on board, Read Enable and Write Enable signals now generated on chip. 256 RAM, 8 channel 8 bit A/D.
HC11 D Series
Smallest and lowest cost member of the hc11 Family. ROMless (D0), 4K ROM (D3), 4K EPROM (711D3) - No A-D or EEPROM. Still has standard timers and serial ports.
HC11 E Series
Same as A series except 512 bytes RAM and 512 EEPROM (2048 for E2). Pin compatible, only difference is one timer pin (PA4) can now be used for IC or OC instead of just OC. Also have EPROM devices and larger memory - hc711e9 (12K OTP), hc711e20 (20K OTP).
HC11 F Series
ROMless, non multiplexed address/data bus with 4 chip selects built in. 1K RAM, 512 bytes EEPROM - otherwise same peripherals as E series.
HC11 G Series
16K ROM/EPROM, Non mulitplexed address/data bus, 512 RAM, 4 channel PWM, 10 Bit A/D convertor, 2 separate 16 bit timers.
24K ROM/EPROM, 1Mb addressing using on chip memory mapping. Non multiplexed address and data bus. 4 programmable chip selects, 8 channel 8 bit A/D. 4 channel PWM, 768 bytes RAM.
The 68HC11L6 is based on the 68HC11E9. 16K ROM, additional bidirectional port. Its fully static design allows operation at frequencies down to dc.
HC11 M Series
Large memory modules, 16 bit math coprocessor, 4 channels of DMA.
HC11 P Series
Programmable PLL- based clock circuit, many 1/0 pins, large memory and 3 SCI ports.
And there are many more ...
this Motorola page.